STUDIES IN ENGINEERING AND EXACT SCIENCES <p>The <strong>STUDIES IN ENGINEERING AND EXACT SCIENCES (SEES)</strong> publish an academic-scientific article on topics related to the areas of Engineering and Exact Sciences, plus the subfields, Civil Engineering, Mining Engineering, Materials and Metallurgical Engineering, Electrical Engineering, Mechanical Engineering, Chemical Engineering, Sanitary Engineering, Production Engineering, Nuclear Engineering, Transportation Engineering, Marine and Ocean Engineering, Aerospace Engineering, Biomedical Engineering, Mathematics, Probability and Statistics, Computer Science, Astronomy, Physics, Chemistry.</p> <p style="margin: 0cm; margin-bottom: .0001pt; text-align: justify; background: white;">The SEES accepts contributions written in <strong style="box-sizing: border-box;">Portuguese</strong>, <strong style="box-sizing: border-box;">English</strong> or <strong style="box-sizing: border-box;">Spanish</strong>.</p> <p>DOI prefix of SEES: <strong>10.54021</strong></p> <p style="text-align: justify;">ISSN: <strong>2764-0981</strong></p> <p style="text-align: justify;">Area of ​​knowledge: <strong>Engineering and Exact Sciences, plus the subfields</strong></p> <p> </p> <p> </p> en-US [email protected] (Profa. MSc. Barbara Bonfim) [email protected] (Equipe Editorial) Tue, 02 Jan 2024 19:37:38 +0000 OJS 60 An investigation on the effects of using TMD for vibration control on the response of high-rise buildings to seismic excitation <p>This paper demonstrates that a tuned mass damper (TMD) is capable of effectively reducing vibration in high-rise buildings during seismic events. This study examines the effects of vibration control on the displacements and accelerations of controlled and uncontrolled buildings. It analyses their modal responses using an algorithm in MATLAB software. This study utilised instances of vibration control in models of a six-story and twelve-story skyscraper. The dynamic response of six-story buildings was assessed using two historical earthquakes, namely El Centro (1940) and Boumerdes (2003). The twelve-story skyscraper experienced two further significant earthquakes, namely Northridge (1994) and Kobe (1995). The building has undergone digital simulation, specifically modelling the displacement of the top story. Consequently, the structure equipped with the Tuned Mass Damper (TMD) system exhibits reduced displacement and acceleration compared to the structure without TMD. The implemented TMD system resulted in a displacement reduction of less than 45% in high-rise buildings subjected to seismic excitation.</p> Ali Bousouar, Sallaheddine Harzallah, Bachir Nail, Imad Eddine Tibermacine Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Fri, 05 Jan 2024 00:00:00 +0000 Deep Feature Extraction with Cubic-SVM for Classification of Brain Tumor <p>Brain tumors (BT) are fatal and debilitating conditions that shorten the typical lifespan of patients. Patients with BTs who receive inadequate treatment and an incorrect diagnosis have a lower chance of survival. Magnetic resonance imaging (MRI) is often employed to assess the tumor. However, because of the massive quantity of data provided by MRI, early BT detection is a complex and time-consuming procedure in biomedical imaging. As a consequence, an automated and efficient strategy is required. The detection of brain tumors or malignancies has been done using a variety of conventional machine learning (ML) approaches. The manually collected properties, however, provide the main problem with these models. The constraints previously stated are addressed by the fusion deep learning model for binary classification of BTs that is presented in this study. The recommended method combines two different CNN (Efficientnetb0, VGG-19) models that automatically extract features and make use of the feature’s classification using a Cubic SVM classifier model. Additionally, the recommended approach displayed outstanding performance in various classification measures, including Accuracy (99.78%), Precision (99.78%), Recall (99.78%), and F1-Score (99.78%), on the same Kaggle (Br35H) dataset. The proposed strategy performs better than current approaches for classifying BTs from MRI images.</p> Mohammed Bourennane, Hilal Naimi, Elbar Mohamed Copyright (c) 2024 Fri, 12 Jan 2024 00:00:00 +0000 An efficient primal-dual interior point algorithm for linear optimization problems based on a new parameterized Kernel function with a logarithmic barrier term <p>In this paper, we present a primal-dual interior point method for linear optimization problems based on a new Kernel function with on a new parameterized logarithmic barrier term. We prove that the proposed kernel function belongs to the eligible class. We derive the complexity bounds for large and small-update methods respectively.</p> Fatima Boukhenchouche, El Amir Djeffal Copyright (c) 2024 Fri, 12 Jan 2024 00:00:00 +0000 Effects of glass powder and Gypsum (Timchemt) on the thermal and mechanical properties of plaster bricks <p>The present research aims to study the effect of glass powder extracted from the glass waste disposal area in Ouargla (southern Algeria) on the thermo mechanical properties of plaster bricks. Therefore, density, compressive strength, flexural strength, thermal conductivity, and thermal resistance were measured in the laboratory using mixtures generated through the response surface methodology (RSM). This RSM technique was used to assess the influence of gypsum (95% – 100%) and glass powder (0% – 5%) on the behavior of hardened plaster bricks. The experimental results and RSM evaluation show a significant increase in compressive and flexural strength at the maximum and minimum levels of Timchemt and glass powder, and detailed scanning electron microscopy (SEM) analyses supported the results. Consequently, quadratic mathematical models were developed using the RSM method applied to the obtained results. Analysis of variance (ANOVA) yielded a (P-value &lt;0.05) and correlations exceeding 91% for all the studied parameters. Probability plots showed excellent correlation between predicted and experimental values, and the 2D and 3D contours of the RSM demonstrated that the fitted models work very well and can provide the appropriate relationship between the selected parameters and thermo mechanical properties.</p> Samia Bouzouaid, Hachem Chaib Copyright (c) 2024 Fri, 19 Jan 2024 00:00:00 +0000 Improvement axial dispersion calculation in fibrous garnished fixed beds using the neural method <p>To determine accurately the physical modeling of flow through porous media and / or in chemical reactors, especially in the field of low Reynolds numbers, it is essential to compute the coefficient of axial dispersion. In prior studies, we employed the neural method to compute axial dispersion within fixed beds with parallelepiped and spherical packings. In the present study we apply the same method of calculation on heterogeneous fixed beds with large anisotropy using data from Poirier and Trinh on fibrous beds. Such an investigation could be however very useful while one has the desire to predict the mixing process to characterize the axial dispersion in fixed beds of anisotropic particles andwhenexperimental measurements are not accessible and / or difficult to implement as for reactors and / or industrial complex porous media. To show also the robustness and applicability of this method, the calculation results obtained will be modeled using expressions similar to those proposed by Poirier and Trinh, so that we can compare our results with those obtained by these authors, under the same operating conditions. Furthermore, our study offers a comprehensive analysis encompassing all three examined fixed bed configurations, namely parallelepiped, spherical, and fibrous arrangements.</p> Djamel Hassani, Faouzi Didi, Salah Hanini, Kamel Daoud Copyright (c) 2024 Mon, 22 Jan 2024 00:00:00 +0000 Management stand-alone hybrid renewable energy system based on wind and solar with battery storage <p>This paper describes the management of a standalone hybrid energy system (HES) based on two renewable sources. The sun, wind. and the battery supports the system. Solar panels and wind turbines (WT) connected with permanent magnet synchronous generators (PMSG) were used for power production. Power converters have been used together with control algorithms for efficient power management. The filters were used to dispose of the largest amount of harmonics in the inverter. The proposed model provides a strategy for managing energy under various generating conditions. In order to save energy for a fixed load. Proposed hybrid accession simulated with MATLAB/Simulink</p> Abdelhak Kechida, Djamal Gozim, Belgacem Toual, Redha Djamel Mohammedi, Elbar Mohamed Copyright (c) 2024 Wed, 24 Jan 2024 00:00:00 +0000 A case study on the evolution of rigid zones within the permanent two-dimensional Herschel-Bulkley fluid flow <p>The formation and development of undeformed regions during the flow of viscoplastic fluids can significantly affect fluid flow behaviour. They can impair the efficiency and effectiveness of industrial operations that use viscoplastic fluids. This paper uses numerical analysis to examine the emergence of rigid zones during non-stationary Herschel-Bulkley fluid flow across a square plate. The impact of pressure and yield stress on the behaviour of rigid zones over time is explored, and the development of the rigid zone area is shown. This work produced mathematical correlations that describe the relationship between the area of rigid zones and both the time of flow and the yield stress, as well as the area of rigid zones and the stagnation time.</p> Messaouda Elalem, Hadi Taibi, Farid Messelmi, Abdelaziz Rabehi Copyright (c) 2024 Fri, 26 Jan 2024 00:00:00 +0000 Optimal placement of phasor measurement units using topology transformation method based on Grey Wolf optimization approach <p>The optimal placement of phasor measurement units (PMUs) requires minimizing both the number of PMUs required and ensure that the whole power system is totally observable. To identify a power system as observable, it is necessary to know the voltages of all the buses in the power system. This paper suggests rules of selection for the topology transformation method, which implies a process of merging a zero injection bus and one of its neighboring buses. The selection of a bus chosen to merge with a zero injection bus will affect the result of the merging process. To determine the most appropriate bus to merge with the zero injection bus, the proposed method will use four rules designed to determine the minimum number of PMUs required to achieve full observability of the power system. The problem is formulated and solved by a grey wolf optimization (GWO) approach. The suggested GWO has been applied to the IEEE 14-bus, 24-bus, and New England 39-bus.</p> Ridha Djamel Mohammedi, Djamal Gozim, Abdelkader Azzeddine Laouid, Mohamed Elbar Copyright (c) 2024 Mon, 29 Jan 2024 00:00:00 +0000 Preparation and characterization of ultrafiltration membranes derived from recycled Polyethylene terephthalate (PET) bottles <p>The pressing need for sustainable practices and eco-friendly materials in the face of escalating environmental concerns has led to exploring the transformation of discarded polyethylene terephthalate (PET) bottles into functional ultrafiltration membranes. This research prepares and characterizes ultrafiltration membranes derived from PET bottle waste. The study involves collecting PET waste material and fabrication processes to develop asymmetric flat sheet membranes blended with varying proportions of hydrophilic polyethylene glycol (PEG) using phase inversion techniques. Rigorous characterization employing SEM, EDS analysis, and water vapor permeability (WVP) assessments examine these membranes' structural, morphological, and performance attributes. The surface analysis elucidates a notable correlation between increased PEG content and larger pore sizes, consistent with prior studies involving PEG in membrane modifications. Additionally, incorporating PEG in the casting solution elevates water vapor permeability. Ultrafiltration experiments reveal differing rejection rates, with membrane M2 exhibiting enhanced anti-fouling properties despite reduced flux compared to M3 and M4. This research lays the groundwork for repurposing PET waste into selective membrane materials, emphasizing optimization strategies to enhance membrane quality and performance for diverse operational settings.</p> Mohammed Amin Chemrak, Abdelkader Chougui, Mustapha Hafani, Sara Chourouk Benali, Djellal Adda Benattia, M’hammed Djennad Copyright (c) 2024 Mon, 29 Jan 2024 00:00:00 +0000 Análise da acessibilidade de áreas internas e externas de ginásios de escolas públicas de Chapecó (SC) <p>A acessibilidade nas edificações é um direito fundamental do cidadão para uso com segurança dos espaços públicos ou privados. Todos os locais devem apresentar acesso para pessoas portadoras de deficiência ou com mobilidade reduzida. A falta de acessibilidade em ginásios esportivos dificulta a prática de esportes, bem como a possibilidade de participação em eventos realizados nestes ambientes. Neste contexto, na presente pesquisa, foi realizada a avaliação da acessibilidade das áreas internas e externas de ginásios de 10 escolas públicas do município de Chapecó (SC), sendo 6 estaduais e 4 municipais. Para o desenvolvimento deste estudo foram realizadas visitas técnicas e aplicação de um <em>cheklist </em>com base nas normas técnicas brasileiras sobre acessibilidade. Os resultados mostraram que nenhum ginásio avaliado apresentou acessibilidade total. Ainda os ginásios das escolas estaduais apresentaram melhor desempenho de acessibilidade quando comparados com os ginásios das escolas municipais. A falta de acessibilidade nas áreas internas e externas dos ginásios das escolas públicas do município de Chapecó (SC) dificulta a participação de todos os cidadãos nestes locais, não garantindo a liberdade de locomoção em segurança.</p> Vanessa Sabka Pigosso, Ariane Castegnera, Eliz Paula Manfroi Copyright (c) 2024 Mon, 29 Jan 2024 00:00:00 +0000 A novel methodology for transformer winding defects diagnosis based on its measured frequency response signal impedance morphology interpretation <p class="Dadosautores">This article proposes the characteristics study of the key parameters of power transformer winding (viz. the equivalent capacitance and the equivalent inductance) extracted from the frequency response analysis (FRA) of the winding. However, the FRA curve of the winding can be divided into three frequency ranges (low, medium, and high), where; the low and the high frequency response (LFR and HFR) ranges represent the inductive and capacitive effects of the winding respectively, which can establish best analysing and interpreting tool of the winding response behaviour to diagnose their failures. Furthermore, real axial deformations were carried out on a winding constructed for this study. In addition, the variation of the equivalent inductance and capacitance obtained from the impedance curve in the LFR and HFR ranges were analysed to locate and evaluate the faulty states with the reference state of the winding. Consequently, the proposed method provides a tool for locating and assessing the internal faults severity in power transformer windings.</p> Moustafa Sahnoune Chaouche, Faouzi Didi, Abderrazak Amara, Rachid Sahnoune Chaouche, Hamza Houassine Copyright (c) 2024 Wed, 31 Jan 2024 00:00:00 +0000 Time history analysis of structures under multi-support excitation by state-space method <p class="Dadosautores">Because of the variety of methods to simulate the dynamic behaviors of the structure under earthquake loading trying to approach the reality. This paper provides a contribution to simulate this behavior using three methods, mainly starting with state space. Secondly, we compare it with the finite element method (Duhamel integral and direct method of Newmark), taking into consideration the effect of Non-uniform excitation in the supports. The obtained results proves the three methods are efficient and very close to each other for simple structures but in term the computing time, the state space method is faster than the others. At the end, add a big structure to test the limits of each method.</p> Mohamed Guesmi, Nassira Belkheiri, Mohamed Lakhder Guesmi Copyright (c) 2024 Wed, 31 Jan 2024 00:00:00 +0000 An investigation on the shear deformation under bending conditions of cantilever FGM beams using a new polynomial shear function <p>In this paper, a static analysis to establish a mathematical model using high order bending theories considering shear strains in displacement fields which have not been taken into account by other theories for functionally graded material (FGM) cantilever beams under bending. A new polynomial shear function is used in this investigation, when satisfied the stress-free boundary conditions. These theories do not require a shear correction factor and consider a hyperbolic shape function. Material properties are assumed to vary in the thickness direction, a simple power-law distribution in terms of volume fractions of constituents is considered. Illustrative cases, a cantilever FGM beam subjected to a concentrated shear force at the free end, and also as a cantilever FGM beam with uniformly distributed load are presented the originality of this research work, in this investigation. The mathematical model is established by differential equations which are derived by the principle of virtual work. Equilibrium equations and boundary conditions are introduced. The solution model is based on a variation approach (integrals) to predict the field component of displacements and the basic constitutive laws. The solution of the analytical model is presented. The results in terms of displacement fields including rotation of the section, and shear stresses, predicted from&nbsp;&nbsp;&nbsp; the proposed model, are presented.</p> Aissa Boussouar, Attia Bachiri, Bachir Taallah, Ali Zaidi Copyright (c) 2024 Tue, 06 Feb 2024 00:00:00 +0000 Quantification of water losses and performance analysis of drinking water supply systems in northern Algeria - case study in the Medea region <p>This study was prompted by the observation of the great difficulties that affect the public provision of drinking water in Algeria. The analysis of measurements revealed the performance level of the tested systems as well as the rates of drinking water losses rates in the Medea region (located 60 km southwest of Algiers). The small number of water meters and an intermittent supply make it difficult to quantify water volume losses. This article presents an analysis of the demand for drinking water and the supply systems performance, based on an extrapolation from a sample of consumers on whom data are available. This approach to exploring the current state of the drinking water system, its functioning and behaviour, has made it possible to draw up a report on this system’s reliability even in the almost total absence of metering of the consumed volumes. It will also help appreciate the quality of service and contribute to establishing relevant database on the water system and its service.</p> Lassaad Gouacem, Rachid Masmoudi Copyright (c) 2024 Tue, 06 Feb 2024 00:00:00 +0000 Dispositivos tecnológicos para avaliações ergonômicas das atividades desempenhadas em atividades laborais: uma revisão sistemática <p>As tecnologias relacionadas à Internet das Coisas <em>(Internet of Things – IoT</em>) estão criando novas interações sociotécnicas entre dispositivos tecnológicos e seus usuários de modo a melhorar a qualidade e bem-estar dos trabalhadores. Apesar do crescimento no interesse pelas tecnologias IoT, a literatura ainda carece de informações sobre dispositivos tecnológicos direcionads a avaliações ergonômicas de atividade laborais. Por meio de uma Revisão Sistemática de Literatura, o presente estudo possui o objetivo de identificar os dispositivos tecnológicos presentes na literatura de avaliação ergonômica dos profissionais. Foram identificados 67 artigos pertinentes ao tema e considerados para revisão. A partir dos resultados obtidos, destaca-se a relevância do número de estudos direcionados para aplicação dos <em>dispositivos Inertial Measurement Units</em> (IMUs), sobretudo para avaliação de profissionais no ambiente industrial. Como principal contribuição, o presente estudo reporta oportunidades de pesquisa relacionadas a aplicações dos dispositivos tecnológicos estudados em áreas profissionais ainda pouco exploradas.</p> Davi Avelino da Silva, Luiz Philipi Calegari, Eugenio Andrés Diaz Merino, Gisele Schmidt Diaz Merino Copyright (c) 2024 Fri, 09 Feb 2024 00:00:00 +0000 Implementing distributed collaboration and applying the YOLO algorithm to robots <p>Recently, the world has witnessed the development of artificial intelligence and robot programming, which have enabled robots to work together to perform specific assigned tasks while overcoming obstacles in the environment. Robots can now operate independently of each other. In this research, four-wheeled robots were created in webots and placed in different environments in Gazebo. These robots are associated with LIDAR and Kinect cameras. Due to the distributed collaboration between robots, a robot cannot traverse a path that it has previously traversed. The three robots are given the same goal, and the first robot to reach the goal signals the end of the mission to the remaining robots and learns about the surrounding objects on the way to the goal. Therefore, the YOLO algorithm was used (You Only Look Once). This is one of the best algorithms for detecting objects in their environment. Regarding the results obtained in the simulation, the robot performed all the assigned tasks.</p> Wissam Hanafi , Mohammed Tamali Copyright (c) 2024 Wed, 14 Feb 2024 00:00:00 +0000 Verification and identification of the speech signal using algebraic analysis and DWT <p>We presented a flowchart, of a new approach that relies on the mathematical operations of matrices and to verify and identifies the speaker, this is a new method difficult to detect by attackers, and this is due to the difficulty to determine its base matrix used in the speaker verification and identification process, Although there are many artificial intelligence programs that can imitate voices and generating false conversations, which poses security and hacking problems.</p> Amraoui Abdelkader, Saadi Slami Copyright (c) 2024 Wed, 14 Feb 2024 00:00:00 +0000 Effect of ultrathin glass substrate on the stability of perovskite CH3NH3PbI3 layer <p>In this work, we investigated the effect of two different substrate types on the structural and optical characteristics of the CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> perovskite layer: soda-lime glass (SLG) and borosilicate glass (UTG). Subsequently, we examined the samples' stability by measuring their absorbance following 120 hours of exposure to the local ambient conditions in Djelfa, Algeria. The absence of OH groups in the UTG substrate as revealed by FTIR may be the reason for the notable impact of the UTG substrate over the SLG substrate on perovskite characteristics. This absence indicates that the inorganic element's influence on the perovskite significantly diminishes, and in this instance, the matrix endures for an extended period within the local metrological restrictions.</p> Aicha Aziza Ayad, Abdelkrim Naas, Noureddine Selmi, Omar Meglali Copyright (c) 2024 Mon, 19 Feb 2024 00:00:00 +0000 Determinação da estrutura cristalográfica de nanopartículas metálicas <p>Neste artigo será apresentado resultados envolvendo determinação estrutural de nanopartículas metálicas. A formação de nanopartículas metálicas suportadas de 4 ML de espessura foi obtida por aquecimento de um filme de Rh sobre uma superfície ordenada de óxido de cromo. A estrutura cristalográfica foi investigada por X-ray Photoelectron Diffraction (XPD) e Low Energy Electron Diffraction (LEED). A composição e a estrutura eletronica foi verificada por X-ray Photoelectron Spectroscopy (XPS). Para modelar os resultados experimentais foi utilizado simulação de espalhamento múltiplo de elétrons. Neste trabalho foi observado que as nanoparticulas de Rh cresceram seguindo o empacotamento do substrato e um aumento no parâmetro de rede do Rh. Também foi observado uma pequena contração na primeira distância interplanar e uma expansão na segunda distância interplanar.</p> Amaro Vinícius Medeiros Ferreira, Cléria de Lourdes Teodoro Pancotti, Amanda Santos Abreu, Enzo Lucas Breancini, Alexandre Pancotti Copyright (c) 2024 Tue, 20 Feb 2024 00:00:00 +0000 Efficient control of three-phase cascaded multilevel Z-Source inverter using SHEPWM technique <p>This paper presents an enhanced control strategy for three-phase cascaded multilevel Z-source inverters, focusing on the implementation of Selective Harmonic Elimination Pulse Width Modulation (SHEPWM) techniques to improve efficiency. Z-source inverters are gaining prominence in various applications due to their inherent advantages, such as increased voltage boost capability and inherent shoot-through protection. However, achieving optimal control in cascaded multilevel configurations poses challenges that this study seeks to address. The proposed control strategy optimizes the switching patterns of the inverter, thereby enhancing its overall performance. It allows for precise control over the output voltage and reduces harmonic distortion, ensuring the inverter operates efficiently across varying load conditions. The research methodology involves a comprehensive analysis of the proposed technique, including its mathematical modeling and simulation using advanced software tools. Performance metrics such as total harmonic distortion, efficiency, and transient response are evaluated to quantify the improvements achieved. The results obtained demonstrate the efficiency of the proposed control strategy. This method significantly reduces harmonic distortion in the output voltage, leading to improved power quality. Furthermore, the efficiency of the inverter is enhanced, making it suitable for applications demanding high-performance power conversion.</p> Benyoucef Kaddour, Noureddine Henini, Abdelhalim Tlemçani, Mohamed Allali Copyright (c) 2024 Wed, 21 Feb 2024 00:00:00 +0000 A framework to quantify battery degradation in residential microgrid operate with maximum self-consumption based energy management system <p>Battery Energy Storage System (BESS) is a crucial component for improving the performance of Hybrid Renewable Energy System (HRES) based microgrid. This paper aims to quantify the battery capacity fade due to battery charging/discharging cycling in a DC microgrid operate with well-known rule-based energy management system, Hence, based on a reduced-order physical model for Lithium-ion battery degradation, a framework was established to assess the state of health (SOH) of the battery. The simulation results show that limiting charging/discharging cycling help in prevent high-capacity loss, however its effect on the self-consumption and self-sufficiency in residential remains debatable in the future.</p> Abderrahman Bensalem, Belgacem Toual, Mohamed Elbar, Mohamed Khaleel, Zakaria Belboul Copyright (c) 2024 Wed, 28 Feb 2024 00:00:00 +0000 Multi-objective optimization of machining conditions by geometric programming <p>In metal cutting processes, cutting conditions have an influence on reducing the production cost and time and deciding the quality of a final product. This paper outlines the development of an optimization strategy to determine the optimum cutting parameters for turning processes. Two objective functions are simultaneously optimized under a set of practical of machining constraints, the first objective function is production cost and the second one is the production time. The optimal values of the cutting conditions are found based on the objective function developed for the typified criterion by using a non-linear programming technique called “geometric programming”. In the optimization procedure, the objective functions are subject to constraints of maximum and minimum feed rates and speeds available, cutting power, tool life, deflection of work piece, axial pre-load and surface roughness. An example is presented to illustrate the procedure of this technique.</p> Mohamed Djennane, Rachid Benbouta, Allaoua Kherraf Copyright (c) 2024 Wed, 06 Mar 2024 00:00:00 +0000 Fosfato de cálcio intercalado com silano - síntese, caracterização e complexação de Ni(II) <p>A finalidade deste trabalho é o desenvolvimento de um material capaz de adsorver íons metálicos potencialmente corrosivos as partes metálicas de automóveis presentes em combústiveis. Essa nova tecnologia está baseada na síntese do composto cristalino lamelar fosfato de cálcio (CaP) que foi sintetizado adicionando-se uma solução de CaCl<sub>2</sub>.2H<sub>2</sub>O a uma solução de fosfato de amônio dibásico. Na intercalação, o 3-aminopropiltrimetoxisilano (3APTS) foi inserido entre as lamelas, gerando o composto CaP/3APTS. A análise elementar de cálcio e fosfóro para o CaP foram 26,3 e 17,2 %, respectivamente. A quantidade do 3APTS intercalado no CAP foi de 2,3 % de átomos do nitrogênio, que corresponde 1,64 mmol g<sup>-1</sup>. Na micrografia do CaP e do composto intercalado observou a presença de placas paralelas mostrando que a morfologia do cristal é lamelar. Como aplicação o íon metálico divalente, níquel, foi adsorvidos neste material. A adsorção foi obtida a partir da reação do composto intercalado com NiCl<sub>2 </sub>&nbsp;em meio etanólico. A isoterma de adsorção foi ajustada à equação modificada de Langmuir, obtendo-se a linearização da mesma. Através do coeficiente angular calculou-se o valor do coeficiente de seletividade que foi de G = 534 dm<sup>3 </sup>mol<sup>-1</sup> e pelo coeficiente linear obteve-se o valor do número médio de ligantes imobilizados e simultaneamente coordenados a um íon Ni(II) ( &nbsp;= 2). O valor da capacidade máxima de adsorção de Ni(II) foi de 0,69 mmol.g<sup>-1</sup>. Os experimentos de pré-concentração e recuperação de uma solução contendo o íon metálico mostraram que a coluna reteve e recuperou o íon metálico Ni(II) com quase 100% de eficiência.</p> Giovanna França de Araujo, Henrique David João Pabis, Angélica Machi Lazarin Copyright (c) 2024 Fri, 08 Mar 2024 00:00:00 +0000 Novel 2-D cascade ladder-lattice structure recursive digital filters <p>We present in this paper a novel cascade ladder-lattice structure of two-dimensional (2-D) recursive digital filters; this cascade based on two delay units M and N and a basic lattice section. Our new realization has a minimal number of basic lattice sections. Using a transfer function representation; the matrix representations for the basic lattice sections are proposed and used to derive the transfer functions of the realized 2-D digital lattice filters. The theory and transfer functions of the realized 2-D lattice Digital filter are derived. We use the 2-D Givone–Roesser’s state space model to verify the minimal realization of the proposed 2-D recursive digital filte; this later gives matrix-vectors A, b, c and a scalar d which are derived. As result, the dimension of the 2-D generalized state space model is minimal. Finally, several design examples are provided for conducting illustration.</p> Mohamed Zitouni, Thameur Obeidi, Mohamed Elbar, Ahmed Chinoun Copyright (c) 2024 Wed, 13 Mar 2024 00:00:00 +0000 Improving and evaluating the performance of a real photovoltaic pumping system for agricultural irrigation purposes in a desert environment at Ghardaia, Algeria <p>Algeria has one of the highest solar resources in the world. The availability of this significant solar energy can make photovoltaic (PV) water pumping applications a very attractive solution for many uses, including irrigation of agricultural areas, village water supply and domestic uses. The cost of water pumped by a PV pumping system is directly linked to the efficiency and reliability of the different elements constituting the system and also to the solar irradiation available at the installation site. Consequently, it is necessary to improve the reliability and efficiency of the PV generator in order to extract the maximum possible power at all times in order to achieve the most reliable and economic operation. On a real well of 25 m height in desert and semi-arid climate at the Sebseb site, Ghardaïa, Algeria, a typical PV pumping system for irrigation purposes is studied and optimized using two conventionels methods, a P&amp;O method and a incremental method.These methods are essentially based on the assessment of water needs to irrigate 70 palm trees, the data on solar irradiation and the average temperature for the studied site (Sebseb, Ghardaia).</p> Abdelhak Bouchakour, Borni Abdelhalim, Noureddine Benbaha, Zaghba Layachi, Fazzani Amor, Seif Eddine Boukebbous, Abdelaziz Rabehi Copyright (c) 2024 Thu, 14 Mar 2024 00:00:00 +0000 The impact of fibres reinforcement on the thermal characteristics of lime-stabilised compressed earth blocks <p>In civil engineering, the use of fibers in construction has spread recently, because of their many benefits in terms of increasing the cohesion of buildings and their thermal insulation. In addition to having several good physical and mechanical properties. Thermal insulation has become an important thing in the field of construction. Because it is linked to increasing the lifespan of buildings and predicting their thermal behavior. It includes increasing energy efficiency and reducing its costs. Fibers are used to increase thermal insulation, because it creates voids inside the structures that are within its content, and thus impedes the transfer of heat, regardless of the type of transfer by convection, radiation, or conductivity. This study aims to determine the amount of thermal insulation in compressed earth bricks with dimensions of 20 × 10 × 10 cm<sup>3</sup>, to which palm fibers and glass are added in different proportions: 0%, 0.1%, 0.2%, 0.3%, 0.4% and 0.5%.In earthen bricks composed of soil, sand and lime. The study includes the physical, mechanical and thermal properties of these bricks. We focus on thermal insulation in the best samples in terms of hardness. Laboratory samples were taken according to standard experiments in university laboratories. Preliminary results showed a decrease in bulk density between 6% and 8.34%, an increase in mechanical stresses between 42.85% and 45.45%, and an increase in thermal insulation between 26% and 29%. These results give us an overview of the impact of using fibers in construction in terms of increasing weight bearing and predicting the amount of thermal insulation.</p> Fidjah Abdelkader, Oussama Naimi, Rabehi Mohamed, Kezarane Cheikh , Zitouni Tidjani Ahmed, Tayeb Sakhi, Dahmani Roqiya, Chettah Mahieddine Copyright (c) 2024 Thu, 14 Mar 2024 00:00:00 +0000 Fuzzy predictive controller for trajectory tracking of a wheeled mobile robot <p>This paper presents a mobile robot control methodology that uses a fuzzy predictive control system to accurately track given paths. It is specifically designed for scenarios of two successive and distinct paths within a shared reference trajectory. Through the combination of fuzzy logic and predictive control methods, the system aims to significantly enhance tracking accuracy. Modelling the system, using a T-S fuzzy system provides a comprehensive model framework to optimize the tracking process. Furthermore, the use of a well-tuned fuzzy system facilitates dynamic adjustments of the weighting matrices of the predictive controller. The combination of fuzzy logic and predictive techniques results in a robust control system capable of handling complex tracking tasks. The simulation results describe the accuracy, robustness, and efficiency of the suggested control strategy. The system is particularly effective in scenarios with two successive paths within a shared reference trajectory, where precise tracking is essential. This approach is crucial for mobile robots or vehicles navigating complex, changing environments.</p> Mohamed Elamine Hedroug, El Khansa Bdirina, Kamel Guesmi Copyright (c) 2024 Thu, 14 Mar 2024 00:00:00 +0000 Influence of calcined dam mud on the thermal conductivity of binary and ternary self-compacting concrete mixtures using the equivalent mortar method <p>Reducing energy consumption in concrete buildings requires cement-based structural materials that have low thermal conductivity. Moreover, low thermal conductivity is a crucial property of building materials used for thermal insulation to ensure the comfort of building occupants. The research evaluates the effect of using calcined mud (CM) and natural pozzolan (Pz) on the thermal conductivity of self-compacting concrete (SCC). To optimise SCC formulations, the equivalent concrete mortar method has been used. This communication mainly focuses on the equivalent self-compacting concrete mortars (ESCCMs). The current study consists of ten formulations: one control (based on Portland cement) and nine others containing binary and ternary systems of Portland cement, calcined mud, and natural pozzolan with 10%, 20%, and 30% replacement rates . The mixtures were prepared using tests of cement paste and equivalent mortar in a fresh state. Afterwards, they were assessed based on their compressive strength at 14, 28, 90, and 180 days and their thermal conductivity at 28 and 90 days in the hardened state. The self-compatibility, the thermal conductivity, and the mechanical performance results obtained by relevant tests on ESCCMs prove that the ternary systems (Portland cement, CM, and Pz) open up many techno-economic development avenues in SCC applications to be explored.</p> Hind Hidayet Sallai, Nasr Eddine Bouhamou, Hafida Marouf , Abdelkadir Belghit, Abdulkadir Cüneyt Aydin Copyright (c) 2024 Fri, 15 Mar 2024 00:00:00 +0000 Model order reduction, a novel method using krylov sub-spaces and genetic algorithm <p>Model Order Reduction (MOR) of complex and large systems in Electrical engineering, continuous to be an attractive field for Engineers and Scientists over the last few decades, this complexity of models makes the control designs and simulation using Computer Aided Design (CAD) more and more difficult and consuming a lot of time. There for, accurate, robust and fast algorithms for simulation are needed. The goal of MOR is to replace the original system by an appropriate reduced system which preserves the main properties of the original one such that stability and passivity. Several analytical MOR techniques have been proposed in the literature over the past few decades, to approximate high order linear dynamic systems like Krylov sub-space techniques and SVD (Singular Value Decomposition) techniques. However, most of these techniques lead to computationally demanding, time consuming, iterative procedures that usually result in non-robustly stable models with poor frequency response resemblance to the original high order model in some frequency ranges. Recently a set of new techniques based on Artificial Intelligence (AI) were proposed in [1] for MOR. This article considers the problem of model order reduction of Linear Time In varying (LTI) systems. It is described by first and second order ordinary differential equations model. A tow steps method for model order reduction of LTI systems is proposed here, which combined features of an analytic technique (Krylov approach) and an AI technique (Genetic Algorithm). In the first step, the size of the original model is reduced to an intermediate order, using an analytical technique based on Krylov sub-spaces. In the final step of the reduction process, an AI approach based on Genetic Algorithm (GA) is applied to obtain an optimized nominal model.</p> Abdesselam Tamri, Amel Baha Houda Adamou-Mitiche, Lahcène Mitiche Copyright (c) 2024 Wed, 20 Mar 2024 00:00:00 +0000 Effects of acidic environments and sorptivity on high-performance concrete containing natural pozzolan and limestone filler <p class="Dadosautores">Even though high-performance concrete (HPC) is a more robust type of concrete, acidic environments can still have a negative impact on it.<span style="color: #1f1f1f; background: white;"> Acids can dissolve other </span><span style="background: white;">components in the concrete as well, leading to a loss of material and increased porosity. This makes the concrete even more susceptible to further degradation. Acidic environments attack the calcium hydroxide (CH), a key component of the cement paste that binds the aggregate in concrete. This reaction weakens the structure and reduces the overall strength of the concrete. </span>The purpose of this study is to assess how HPC containing natural pozzolan (NP) and limestone filler (LF) responds to acidic environments and sorptivity. The cement (PC) was replaced by NP and LF in different mass proportions. The mixtures HPCC (100% PC), HPC18 (10%LF + 90%PC), HPC7 (20%NP + 80%PC), and HPC14 (5%LF + 10%NP + 85%PC) were prepared. The sorptivity was evaluated by measuring the sorptivity coefficient (S, cm*s<sup>-0.5</sup>) after 28 days of submersion in distilled water. HPC specimens were submersed in distilled water, 5% sulfuric acid (H<sub>2</sub>SO<sub>4</sub>), and 5% hydrochloric acid (HCl) for up to 180 days in order to test their acid resistance. Visual inspection and changes in mass were used to evaluate the specimens' resistance to acid attack. The results showed that replacing PC with LF and NP reduced the sorptivity of HPC. Substituting 10% of PC mass with LF increased the HPC's resistance to sulfuric acid. However, substituting the PC with NP and/or LF reduced the HPC's resistance to hydrochloric acid. According to visual inspection and mass losses, the sulfuric acid was more aggressive than hydrochloric acid.</p> Tarek Hadji, Ahmed Attia, Taha Hocine Douara, Salim Guettala, Michèle Queneudec Copyright (c) 2024 Wed, 20 Mar 2024 00:00:00 +0000 On the of seawater desalination environmental impacts and brine treatment based challenges and mitigation measures in Algeria <p>In this paper the environmental impacts of seawater desalination is investigated and highlighted. Indeed despite the various benefits of desalination there is growing apprehension about the potential negative environmental effects it may bring and generate. Both during the plant construction and its operation service. There is the possibility of leading and causing adverse environmental impacts. A significant concern with desalination is the co-produced and generated waste known as 'brine' or 'reject,' which contains high salinity as well as chemical residuals which are released into the marine environment. Viable and cost-effective brine management systems are necessary to mitigate the negative impact of brine, also referred to as concentrate, which is a by-product of the desalination process. This high salinity substance poses a threat to the environment and must be managed effectively in order to reduce pollution. Aside from brine other difficulties include marine species entrainment and trapping, as well as high chemical use. This paper provides an extensive overview and evaluation of desalination technologies used in Algeria including thermal methods such as Multi-Stage Flash (MSF) and Multiple Effect Distillation (MED) as well as Membrane Reverse Osmosis (RO). Furthermore in order to assess the potential environmental implications of desalination and brine treatment on the Algerian coast, mitigation strategies are proposed to curb the environmental negative impact. To protect water resources for present and future generations, improved brine management techniques are needed to minimize adverse environmental effects and lower the financial burden of disposal. This will encourage further advancements in desalination plants. Ultimately, the paper emphasizes upcoming research opportunities in brine treatment technologies with a focus on improving the efficiency and sustainability of desalination.</p> Oussama Naimi , Lousdad Abdelkader, Fidjah Abdelkader, Hassiba Bouabdesselam, Mohammed Chemsedine Ezzine, Belatoui Abdelmalek, Mokhtari Mohamed, Smain Nour Elhouda Copyright (c) 2024 Wed, 20 Mar 2024 00:00:00 +0000 Seismic vulnerability assessment of buried water supply and sanitation pipelines using the analytic hierarchy process: a methodology and application <p>The evaluation of seismic vulnerability in buried pipelines within water supply and sanitation networks stands as a critical endeavor in safeguarding infrastructure against the impacts of earthquakes. In response, this study introduces a systematic methodology rooted in the Vulnerability Index (VI), leveraging the Analytic Hierarchy Process (AHP) to allocate weights to factors influencing pipeline seismic behavior. Through the derivation of an expression for calculating the VI based on these weighted factors, our objective is to furnish a comprehensive pipeline classification system, thereby providing a strategic overview of the networks' seismic resilience. This method's practical utility will be exemplified through the examination of concrete cases involving drinking water pipelines (DWP). Furthermore, the scope will extend to encompass sanitation pipelines, thereby validating the methodology's effectiveness across both domains. By systematically assessing the seismic vulnerability of these crucial infrastructures, we aim to fortify their resilience against seismic events, ensuring the continued provision of essential services even in the face of natural disasters. This study's significance lies not only in its contribution to the field of infrastructure resilience but also in its practical implications for urban planning and disaster management. By elucidating the factors influencing pipeline vulnerability and providing a robust framework for assessment, decision-makers can better prioritize resource allocation and mitigation efforts, ultimately enhancing community safety and well-being. Furthermore, the methodology's adaptability and scalability render it applicable to diverse contexts, facilitating its integration into broader risk management strategies. As such, this study serves as a valuable tool for policymakers, engineers, and stakeholders seeking to enhance the resilience of water supply and sanitation networks in earthquake-prone regions. Through informed decision-making and proactive measures, we can build more resilient communities capable of withstanding the challenges posed by seismic hazards.</p> Fatma Zohra Halfaya, Mahmoud Bensaibi Copyright (c) 2024 Wed, 20 Mar 2024 00:00:00 +0000 Magnetic rotor breakage study in permanent magnet synchronous motor at COMSOL multiphysics and fault detection using machine learning <p>Electric vehicles are one of the most important means in the industrial sector due to their frequent use and depend primarily on electric motors. Electric motors of all types, synchronous and asynchronous, face many faults in the rotor and stator, affecting the performance's reliability. Researchers are seeking to find ways that enable us to detect and diagnose faults in electric motors based on smart and fast methods. Early detection of problems in electric motors is vital, especially in areas such as electric vehicles. This study focuses on magnetic rotor breakage (MRB) in permanent magnet synchronous motors (PMSM). We use a simulation tool such as COMSOL Multiphysics as a simulation tool. This platform is a widely used software for modeling and analyzing complex electromagnetic systems. The study also addresses fault detection using machine learning. This involves using data analysis and pattern recognition techniques to distinguish between normal and defective states of the motor. This is an important step to improve the reliability of motors and identify potential failures in advance. Five different machine learning algorithms such as Extreme Gradient Boosting (XGBoost), AdaBoost, Gradient Boosting (GB), Naive Bayes (NB), and Random Forest (RF) are used in the study. Data from four different cases obtained from the PMSM design were used to train and test the machine-learning models. The results obtained show how accurate the proposed models are in diagnosing PMSM problems, especially MRB.</p> Said Benkaihoul, Lakhdar Mazouz, Toufik Tayeb Naas, Özüpak Yıldırım, Amar Regaz Copyright (c) 2024 Wed, 20 Mar 2024 00:00:00 +0000 An experimental investigation to predict the durability of polyester-glass fiber composite subjected to tensile loading <p>Glass Fiber and resin composites represent a significant advance in the industry thanks to their lightness, strength, and versatility. Their mechanical strength, highlighting a number of critical aspects in the development of high-performance materials, opens up new prospects in sectors as diverse as aerospace, automotive, and construction, among others. These advances stimulate ongoing research and development in the field of composite materials, underlining the importance of these efforts in meeting future needs in terms of materials performance and durability. This study examines the capacity to predict the durability of polyester-glass fiber composites when subjected to tensile loading. The experimental approach involves exploring the mechanical properties of the composite material and changes in glass fiber content, fiber length, and plate thickness. The process includes performing tensile tests on composite specimens to assess characteristics like Young's modulus and fracture stress. The study uses analytical prediction tools, precisely the Monte Carlo approach, to evaluate the damage distribution within the composite material. The study emphasizes the substantial influence of glass fiber content with a maximum content of 60% mass resin and length with the optimum size of 60 mm on the mechanical properties where Young's modulus attains a value of 4 GPa and longevity of the composite. The study highlights the significance of plate thickness in improving structural performance and fracture toughness, where Young's modulus shows consistency across varying thicknesses. In contrast, stress shows an increasing trend with thickness, culminating in a value of 3.4 MPa. The results enhance comprehension of polyester-glass fiber composites' mechanical characteristics and prediction ability under tensile stress.</p> Djamila Mokhtar, Malika Medjahdi, Belaid Mechab, Noureddine Benderdouche, Benaouda Bestani, Mohammed Amin Chemrak Copyright (c) 2024 Thu, 21 Mar 2024 00:00:00 +0000 A Pushover analysis approach considering structural and loading uncertainties for seismic performance assessment <p>This paper proposes an approach for evaluating the seismic performance of buildings. By considering the uncertainties in material and geometrical properties of the structural elements as well as those related to the seismic loading, this method aims to delimit the performance zone of the structure rather than focusing on a single performance point commonly used in pushover analysis. This zone makes it possible to identify the probable levels of performance of the building linked to uncertainties and to indicate the most severe level of damage. Reasoning by performance points leads to an answer that gives a single state of damage. The performance zone is defined by capacity curves and response spectrum representing the mean values plus and minus standard deviation obtained by Monte Carlo simulations. These simulations consider the stiffnesses of the structural elements, the natural periods, and the damping ratio of the response spectrum as random variables. The application of the procedure to a case of a building made it possible to identify the upper limit of damage corresponding to the most unfavourable scenario of uncertainties, as well as the situation of the response value of the studied structure in the performance zone, indicating a less critical level of damage (minor damage) to the building. The calculation of the performance point revealed a level of damage oscillating between Immediate Occupancy (IO) and Life Safety (LS). Considering the uncertainties in the material and geometric properties of the structural elements as well as those linked to the response spectrum, the probable extreme damage state is between the LS and CP levels (severe damage).</p> Mohamed Badaoui, Abdallah Yacine Rahmani , Nouredine Bourahla, Sarra Hachi, Mohamed Benyagoub Copyright (c) 2024 Thu, 21 Mar 2024 00:00:00 +0000 A computational fluid dynamics (CFD) modeling in a new design of closed greenhouse <p>Closed greenhouses are crucial buildings for agriculture in controlled environments because they offer the best growing conditions for crops and shield them from outside influences. Researchers can now better optimize design parameters for increased crop output and energy efficiency by simulating airflow and temperature distribution inside closed greenhouses with the use of computational fluid dynamics (CFD) modeling. We examine the temperature distribution and airflow patterns inside the greenhouse under various environmental conditions using CFD simulations. Our findings show that, in comparison to traditional greenhouse constructions, the novel design greatly improves temperature uniformity and lowers energy use. Moreover, the greenhouse's thermal insulation design minimizes heat loss during the colder months, enhancing energy efficiency overall. We offer important insights into how design changes affect airflow dynamics and thermal performance in enclosed greenhouses by utilizing CFD modeling. Our research highlights how effective CFD modeling can be in maximizing crop yields and achieving sustainable agricultural practices through greenhouse design optimization. The integration of novel design components for improved energy efficiency and crop yield is a feasible outcome of this research, which advances the field of closed greenhouse technology overall. The research highlights the value of using CFD modeling to inform the design of next-generation closed greenhouse systems and has important ramifications for sustainable agriculture methods and greenhouse management techniques. The goals were to assess how well various heating/cooling systems maintained the ideal environmental conditions for plant growth. A verified CFD model was used to run the simulations, which took into account a number of variables including the shape of the greenhouse, the outside environment, and the interior heat sources. Important discoveries include understanding temperature gradients, airflow patterns, and possible areas for environmental management enhancement are presented in this paper. Results showed that the species mass transfer of vapor (H2o) will vary over time.</p> Ismail Ghibeche, Ahmed Nourani, Toufik Tayeb Naas, Salah Eddine Benziouche, Martin Buchholz , Reiner Buchholz Copyright (c) 2024 Thu, 21 Mar 2024 00:00:00 +0000 Optimizing self-compacting mortars with fillers from sustainable industrial by-products: evaluation of durability parameters <p>This study investigates the transformative potential of repurposing non-biodegradable industrial by-products, specifically glass, brick, and sanitary ceramic waste, as alternative fillers for self-compacting mortars (SCM). Positioned within the framework of sustainability and enhanced performance, we conduct an in-depth comparative analysis against traditional limestone fillers to ascertain the efficacy of these unconventional materials. Employing a comprehensive methodology, we conduct spreading tests, evaluate heat of hydration, and assess mechanical resistance. Additionally, we delve into key durability parameters, including water-accessible porosity and capillarity, to comprehensively understand the nuanced effects of diverse fillers on the characteristics of the resulting self-compacting mortars. The experimental timeline unfolds through a series of assessments, measuring compressive and tensile strengths at strategic intervals - 2, 7, 28, 90, 270, and 365 days post-application. After 270 days of maturation, our study rigorously examines durability parameters. The findings unequivocally reveal a significant enhancement in SCM performance when incorporating glass, brick, and sanitary ceramic waste as fillers, outperforming conventional limestone fillers. Of notable significance is the consistent superiority of ceramic fillers across a spectrum of metrics. This research significantly contributes to the understanding of sustainable repurposing of industrial by-products in construction. Moreover, it highlights the pivotal role played by ceramic fillers in elevating rheological, mechanical, and durability attributes of self-compacting mortars. Beyond its immediate implications, this study opens new avenues for environmentally responsible and economically viable construction materials, promising further advancements and innovation in the field.</p> Ahmed Messaoud Djebara, Mohamed Mouli , Ramdane Chihaoui, Yassine Senhadji, Abdelkadir Medjahed, Ahmed Soufiane Benosman, Mehdi Seghiri, Karim Belmokretar Copyright (c) 2024 Mon, 25 Mar 2024 00:00:00 +0000 Optimization of date palm waste fiber content and length in sand concrete using the factorial design approach <p>The valorization of some agri-food industry by-products, particularly plant waste, in a number of countries may be significantly interesting in the field of civil engineering because they can be used to prepare low-cost biomaterials that consume low amounts of energy and are environmentally friendly. Recently, it has been revealed that the valorization of date palm fibers (DPFs) waste and incorporating them into concrete may be one of the promising solutions that can be adopted in order to reduce or eliminate the huge amounts of this type of waste from our environment and to improve the properties of concrete. The present work aims primarily to investigate the effect of incorporating date palm waste fibers into sand concrete on the properties of this concrete in the fresh and hardened states. For this, two DPF contents were considered. First, 0.1% of DPFs with lengths 2cm and 6cm, and second 0.2%of DPFs with lengths 2cm and 6cm. Furthermore, a factorial design was used for the purpose of analyzing the influence of varying these two parameters, i.e. fiber content and fiber length, on the physico-mechanical properties of the sand concrete produced. In addition, it should be noted that the response to be considered in this design is the compressive and flexural strengths. Moreover, the JMP statistical software was utilized for analyzing the interactions observed and examining the responses that is predicted by the model generated using the factorial design. The findings showed that the expected responses obtained from the adopted model are in good agreement with the experimental data. Further, it was found that the fiber length factor has a positive effect on the response (strength). However, increasing the DPF content in the formulation of sand concrete has a negative effect on his compressive strength.</p> Ikram Souici, Leila Zeghichi, Abdelhalim Benouis Copyright (c) 2024 Mon, 25 Mar 2024 00:00:00 +0000 Double-diffusive convection of non-newtonian power-law fluids in an inclined porous layer <p>This paper presents a numerical study of Double-Diffusive convection within an inclined porous medium saturated by a non-Newtonian fluid. The power-law model is utilized for modelling the behavior of the flow in the porous layer. The given statement implies that the long side of the cavity experience thermal and solutal flux rates, whereas the other walls are impermeable and thermally isolated. The issue is characterized by a set of tightly linked non-linear differential equations, termed governing equations, encompassing the mass conservation equation (known as the continuity equation), the momentum equation, the energy equation, and the species equation. The relevant factors that govern the problem being investigated are the Rayleigh number, R_T, the power-law index, n, the angle of inclination, Φ, the cavity aspect ratio, A, the Lewis number, Le, the normalized porosity, ξ, and the buoyancy ratio, N, two types of cavity configuration have been studied: inclined cavity (i.e. Φ≠0°), then we have studied the case of a vertical cavity (i.e. Φ=90°) where the buoyancy forces induced by the thermal and solutal effects are opposing each other and of equal intensity (N=-1). A semi-analytical solution, valid for an infinite layer (A&gt;&gt;1), is derived on the basis of the parallel flow approximation, A numerical approach utilizing the finite differences method was utilized to resolve the governing equations within the porous medium. It is demonstrated that both the inclination of the layer, Φ, and the power-law index, n, have a strong influence on the strength of the intensity of flow, Ψ_0, the heat transfer rate, Nu, and the mass transfer rate, Sh, within the enclosure. A good agreement is found between the predictions of the parallel flow approximation and the numerical results obtained by solving the full governing equations.</p> Saleh Khir, Redha Rebhi, Mohamed Kezrane, Faouzi Didi, Selma Lounis Copyright (c) 2024 Wed, 27 Mar 2024 00:00:00 +0000 Fuzzy backstepping control for enhanced stability of a quadrotor unmanned aerial vehicle <p class="Dadosautores">This paper presents a robust fuzzy backstepping control approach to enhance the stability and maneuverability of a Quadrotor Unmanned Aerial Vehicle (UAV). The proposed design combines the robustness of backstepping control with the adaptability of fuzzy logic to address uncertainties and disturbances commonly encountered in UAV dynamics. By incorporating fuzzy logic, the controller can adapt to changing environmental conditions, ensuring reliable performance in various flight scenarios. The backstepping technique enables systematic handling of nonlinear dynamics and achieves precise tracking of desired trajectories. Extensive simulations demonstrate the effectiveness of the proposed control strategy in stabilizing the UAV and enabling agile maneuvers, even in the presence of disturbances and model uncertainties. These results highlight the potential of the proposed approach to enhance the robustness and agility of Quadrotor UAVs in real-world applications.</p> Abdelhafid Benyounes, Abdelghafour Herizi, Mustapha Zegait, Monir Bouras, Bachir Nail, Imad Eddine Tibermacine Copyright (c) 2024 Thu, 28 Mar 2024 00:00:00 +0000 The impact of supplementary cementitious materials on the rheological and mechanical properties of mortars based on quarry waste sand <p>Mineral substances used as additives in cement plants or as additives in the making of concrete contribute through their physical, hydraulic, and pozzolanic activity to improving the behavior of cements in both the fresh and hardened states. Several types of additions are well known, such as natural pozzolans, fly ash, blast furnace slag, and silica fume. These products become more active in the alkaline solutions of cement and give rise to new hydrates that impart greater mechanical strength and better durability to concretes. Through their surface activity and granular distribution, they play a fundamental role in the rheological and mechanical behavior of mortars and concretes. Quarry waste sand (QWS) is generally stockpiled to be eventually sold at very low prices. For this reason, its use in the production of concrete and mortar is increasingly becoming a necessity to protect the environment and meet the needs of the construction and public works sector.This study aims to investigate the effect of using both supplementary cementitious materials (SCM) and quarry waste sand(QWS) to improve some properties of mortar. Ordinary cement is replaced by 10%, 20% and 30% of silica fume (SF), natural pozzolan (NP) or ground blast-furnace slag (GBFS) by weight and the properties of the QWS sand -based mortar are compared to those of natural sand (NS) based mortar. In this study, the slump, superplasticizer requirement, rheological parameters, mechanical strength, and water absorption are investigated. The results obtained show that QWS sand mix has the best workability and requires less superplasticizer dosage. When SCM were used, a drop-in workability is shown and more superplasticizer is required. Also, QWS sand makes the mortar strength 2 and 1.5 times higher than that of NS and becomes 42% higher with 10% SF. Adequate relationships have been established to predict mechanical strengths as a function of test parameters with high correlation coefficient and low root mean square error.</p> Guerbas Nabil, Adem Ait Mohamed Amer, Adjoudj M’hamed, Ezziane Karim Copyright (c) 2024 Thu, 28 Mar 2024 00:00:00 +0000 Enhanced free reaching phase SMC for UMS <p>In this paper, a new design method for sliding mode control (SMC) is presented for nonlinear underactuated mechanical systems. The aim is to eliminate the reaching phase in SMC and avoid the chattering phenomenon while achieving fast and robust tracking for a class of underactuated mechanical systems (UMS). An alternative method is presented to express the sliding domain equations by incorporating tracking errors. The fundamental concept behind the suggested control scheme is to adjust the tracking errors, enabling the system response to commence on the sliding surface regardless of the initial conditions. This modification guarantees the elimination of the reaching phase, avoiding the chattering phenomenon, and ensuring that the tracking error converges to zero. The stability analysis of the proposed approach is conducted using the Lyapunov method. Through numerical simulations, the validity of the approach is confirmed by implementing the control scheme on a crane system. Subsequently, the performance of the proposed approach is compared with other control methods, emphasizing its effectiveness in handling uncertainties. This comparative analysis aims to emphasize the advantages and efficiency of the proposed control strategy over alternative methods, in particular, to address uncertainties and achieve the desired control objectives.</p> Ali Nasser-Eddine Bendenidina, Kamel Guesmi, Aissa Rebai Copyright (c) 2024 Fri, 29 Mar 2024 00:00:00 +0000 Assessing fragility functions of unreinforced masonry buildings <p class="CorpsA" style="text-align: justify;"><span class="Aucun"><span lang="EN-US" style="font-size: 12.0pt; font-family: 'Arial',sans-serif;">The seismic vulnerability entrenched within the historical urban landscapes of Algeria serves as a poignant reminder of the pressing need for comprehensive risk management strategies, particularly concerning low and medium height unreinforced masonry (URM) structures. These architectural gems, rich in cultural significance, stand as tangible embodiments of Algeria's storied past. However, their susceptibility to seismic disturbances presents an immediate threat, demanding meticulous attention and innovative methodologies for effective risk assessment and mitigation. In a pioneering scholarly pursuit, this research embarks on an ambitious exploration, melding fragility functions and a sophisticated vulnerability index method to unravel the intricate tapestry of seismic risk assessment. Through the lens of fragility functions, the study delves into a nuanced analysis, probabilistically delineating the vulnerabilities entrenched within the complex framework of URM buildings. Furthermore, the meticulous derivation of vulnerability functions via the vulnerability index method enhances the granularity of risk assessment, providing a multifaceted perspective to discern vulnerabilities accurately. Central to this investigation is the Belouizdad district, a microcosm of historical significance nestled within the vibrant metropolis of Algiers. By scrutinizing seismic scenarios spanning a spectrum of intensities (ranging from VII to X), the study orchestrates a symphony of empirical data and analytical prowess, unraveling the potential seismic reverberations poised to impact the district's architectural heritage. In essence, this scholarly endeavor transcends the confines of mere academic pursuit, serving as a guiding light illuminating the path towards tailored seismic reduction policies. It stands as a clarion call to safeguard Algeria's architectural patrimony, fostering resilience amidst the tremors of uncertainty and ensuring the preservation of its cultural legacy for generations to come.</span></span></p> Fouzia Djaalali, Mahmoud Bensaibi Copyright (c) 2024 Fri, 29 Mar 2024 00:00:00 +0000 Activator effect on sawdust-based adsorbent efficiency: application to organic pollutants decontamination <p>The aim of this study is to valorize available Sawdust as a ligno-cellulosic and locally abundant solid waste generated by different activities, via combined chemical and physical activations route and its application for the removal of hydroxybenzene as a toxic pollutant from aqueous solution in discontinuous mode. Enhancement of adsorption capacities by impregnating separately the powdered sawdust in acidic (phosphoric acid: 20%), basic (potassium hydroxide: 20%) and salty (Ammonium Persulfate: 0.1M) solutions then pyrolysis at 600°C for 1hour in tubular furnace resulting in SWDA, SWDB and SWDS- based adsorbents. The adsorptive rates of the obtained adsorbents were compared to the commercial activated carbon from Merck taken as a reference. The batch adsorption experiments resulted in a maximum adsorption capacities obtained from Langmuir model of up to 192.31, 123.56 and 109.89 and 133.33 mg/g for SWDA, SWDB, SWDS and Merck respectively. Conventional parameters influencing the removal capacity of the considered pollutant such as contact time, adsorbent dosage, pH, initial concentration and temperature were also studied. Samples characterization was carried out using <em>Fourier</em>-<em>transform infrared spectroscopy</em>&nbsp;(<em>FTIR</em>) analyses for functional groups determination, Iodine number test for porosity and scanning electronic microscopy (SEM) for microstructure examination of the samples. &nbsp;Adsorption kinetics was found to comply with the pseudo second order with a good correlation factor (<em>R<sup>2</sup></em> &gt; 0.99) with intra-particle diffusion as the rate determining steps. Thermodynamics of Hydroxybenzene adsorption process was spontaneous (<em>Δ</em><em>G<sup> o</sup></em> &lt;0) and endothermic (<em>Δ</em><em>H<sup>o</sup></em> &gt;0). This study showed that sawdust as a waste could prove to be a very efficient adsorbent in removing toxic substances from wastewater.</p> Zohra Mekibes, Ahmed Boucherdoud, Benaouda Bestani , Noureddine Benderdouche Copyright (c) 2024 Fri, 29 Mar 2024 00:00:00 +0000 Simulation of damage under cyclic loading for API 5L X70 steel pipelines (fatigue test) <p>The most efficient way to move large volumes of gas and oil is through pipelines, either from points of production to storage locations or from storage locations to distributed points of end use. One of the main materials of gas transportation pipes is X70 material.&nbsp; Base on the importance of in-service API 5L X70 pipelines, it is important for the safe operation of this system to know the lifespan of pipelines, and predict fatigue crack growth (FCG) of API 5L X70 steel pipeline. The objective of this theme is to study the lifespan of pipelines used for the transport of natural gas, oil and water, manufactured by the company ALFAPIPE in the wilaya of Ghardaïa. The judicious choice for manufacturing metal is a crucial factor to ensure prolonged life duration and improve resistance to fatigue, as materials respond to loading with elastic or plastic deformation. Stresses applied to materials can result in permanent deformation, rupture, cracking or progressive degradation. Understanding the effects of applied stresses is essential for the selection and implementation of materials in industrial applications.&nbsp; Fatigue tests were carried out on API 5L X70 steel using simulations using ANSYS software. The life of different samples was determined for different thicknesses after applying repeated stresses. The obtained results demonstrate the material API 5L X70's sensitivity to fatigue and emphasize the significance of designing pipelines with sufficient safety margins to prevent premature failures caused by fatigue.</p> Messaoud Bendaoui, Allaoua Kherraf, Soumia Benbouta Copyright (c) 2024 Fri, 29 Mar 2024 00:00:00 +0000 Experimental investigation and evaluation of the compactness and moisture damage of asphalt mixes incorporating dune and river sand <p>Road construction is mainly based on the use of raw materials that must be in compliance with the standards, thus ensuring the quality and durability of the road. The use of dune sand and river sand in road geotechnics is an interesting subject. Both types of sand can be used in road construction and maintenance for a variety of applications. Dune sand is often appreciated for its uniform grain size and drainage capacity, while river sand can offer good mechanical strength. The majority of common bituminous mixes contain fillers made of quarry sand, whose amounts are difficult to regulate because of the variety of rock deposits and the conditions under which they are manufactured. In this paper, the compactness and moisture damage of asphalt mixes with two sand types, River sand (RS) with (0/4) size was sourced from the valley in the province of Medea (Algeria) and Dune Sand (DS) with a particle size of (0/0.5) was obtained from a dune in the Algerian province of Djelfa, were examined. Furthermore, a 100% replacement rate by weight of Crushed Sand (CS) with (0/3) mm size was used (quarry sand). The investigation employed a comprehensive approach, utilizing Marshall and gyratory shear compaction tests to assess compactness, while moisture damage was evaluated through rigorous water resistance testing and compressive strength methodology. The results of the study reveal a notable disparity in the mechanical performance of asphalt mixtures containing dune and river sand, showcasing diminished compactness and heightened susceptibility to moisture-induced damage when compared to alternative mix formulations. These findings underscore the critical role of sand type selection in asphalt mix design, emphasizing the need for careful consideration to optimize performance and durability.</p> Abderahman Younsi, Abdelhalim Bensaada, Naas Allout, Haddadi Smail, Belgacem Choungache Copyright (c) 2024 Fri, 29 Mar 2024 00:00:00 +0000 Cooling Efficiency of a NACA4412 airfoil: Numerical application <p>The temperatures imposed on the blades of the first stages of turbines are generally very high; these expose the latter to harmful thermal effects, pushing manufacturers to continually improve techniques for cooling the blades. It is true that by increasing the temperature of the gases at the inlet of the turbines, we increase the efficiency, the performance of the machines, and we improve the power and fuel consumption with a significant reduction in polluting gases. Thus, the current general trend among manufacturers is to design machines that operate at increasingly high inlet temperatures. This has led, therefore, to the constant search for new materials with high thermal resistance and to constantly improve cooling techniques. This task is conditioned by a good and deep understanding of the phenomenon of heat transfer in turbine blades. This study examines the three dimension numerical simulation of the flow and heat exchange inside an internal cooling channel of a gas turbine blade with the profile of NACA 4412. This channel plays an important role in increasing heat exchange between the cooling air and the walls of the blade. In the turbulent regime, we have investigated the cooling of a profile blade NACA 4412 using forced convection (V = 200, 250, 300, 350, and 400 m / s). determined that the value of the cold air's speed increases with the intensity of the secondary flow inside the morning. Results found that, The flow dynamics and kinematics of fluid particles alter significantly when the cooling air speed is increased, and the cooling level is enhanced.</p> Toufik Tayeb Naas, Mostefa Telha, Ismail Ghibeche, Omar Mokhtar Khelifa , Salem Ben Abdelhafid Copyright (c) 2024 Wed, 03 Apr 2024 00:00:00 +0000 Assessing road vulnerability in seismic conditions: a comprehensive study <p>Road infrastructure is indispensable for societal functionality, yet it is highly susceptible to the devastating impacts of seismic events. This paper focuses on enhancing the resilience of road systems by systematically identifying, quantifying, and assessing factors contributing to their vulnerability during earthquakes. The core objective of this study is to develop and validate a seismic vulnerability index for road sections, which aims to evaluate and classify the susceptibility of road infrastructure to earthquake-induced damage comprehensively. This systematic approach is pivotal for guiding effective mitigation strategies and prioritization efforts. To fulfill this objective, the study employs the Analytic Hierarchy Process (AHP) to introduce a novel methodology for calculating the seismic vulnerability index, incorporating various factors that influence road vulnerability. This method allows for the accurate classification of road sections into distinct levels of susceptibility, providing a solid foundation for implementing targeted interventions and enhancing road resilience. Further, the paper validates the theoretical model through several case studies, demonstrating the practical applicability and effectiveness of the seismic vulnerability index in real-world scenarios. Additionally, the use of Geographic Information System (GIS) technology to simulate earthquake scenarios within an urban road network offers valuable insights into the potential seismic behavior of roads. These simulations are crucial for identifying critical areas that require intervention and for planning resilience-building efforts more effectively. By proposing a comprehensive framework that combines rigorous analysis, empirical validation, and advanced simulation techniques, this paper seeks to make a significant contribution to the field of infrastructure resilience. It aims to advance the understanding of road vulnerability in seismic conditions and supports the development of strategic approaches for enhancing the resilience of road infrastructure against earthquakes. Through the development and validation of a seismic vulnerability index, this study meets its primary objective, providing a valuable resource for researchers, policymakers, and practitioners in disaster management and infrastructure planning.</p> Sonia Adafer, Mohamed Badaoui, Mahmoud Bensaibi, Saïd Mokhbi Copyright (c) 2024 Wed, 03 Apr 2024 00:00:00 +0000 Improvement of mechanical and interfacial properties (ITZ) of concrete based on treated recycled aggregates <p>The increasing utilization of solid waste from construction and demolition as a raw material for aggregate production for concrete is generating growing interest in the construction and public works industry. This practice contributes to preserving natural resources and reducing waste, which is essential for environmental protection. The use of recycled concrete aggregate (RCA) from demolition waste to produce new concrete, known as recycled aggregates concrete (RAC), is an eco-friendly approach. However, RCAs have poor physical and mechanical properties due to their low density and high absorption, compounded by a low interfacial transition zone (ITZ) compared to natural aggregates (NA). To address these issues, this study proposes encapsulating RCA in a cement slurry (with a water-to-cement ratio of 0.5) and examining the impact of adding 5% silica fume (SF) and 2% water-repellent agent (HF) to the cement grout on the properties of (RCA) made from treated recycled concrete aggregates (RCAT). Two types of treated aggregates, (RCAT-5%FS) and (RCAT-2%HF), were developed and hardened for 15 days in air. They were then used to manufacture RACT concrete. The experimental results demonstrate that the inclusion of (SF) and (HF) effectively enhances the properties of (RCAT). Moreover, the compressive and tensile strengths of RACT-SF are greater than those of the control concrete NAC, estimated at 43.5 MPa and 3.87 MPa, respectively. SEM-EDS analysis confirmed the uniformity of contacts within (ITZ) and assessed the compatibility of the Ca/Si ratio. The addition of silica fume contributed to the creation of solid, durable, and environmentally friendly concrete.</p> Meftah Allal, Leila Zeghichi, Karima Larkat Copyright (c) 2024 Wed, 03 Apr 2024 00:00:00 +0000 Double star permanent magnet synchronous machine: modified direct torque control <p>In the area of high power drives, double star synchronous machines are an interesting choice compared to conventional synchronous machines, due to the relatively low torque ripple created. In this paper, direct torque control (DTC) of double star permanent magnet synchronous machine (DS-PMSM) using artificial neural networks (ANN) is proposed. MATLAB/Simulink results show the comparison between direct torque control (DTC) and direct torque control using artificial neural networks (ANN). The analysis of the results shows good performance for speed, small torque and flow ripple when using the artificial neural network (ANN) strategy.</p> Naas Bachir, Benalia M’hamdi, Amari Abderrahmane , Naas Badreddine Copyright (c) 2024 Fri, 05 Apr 2024 00:00:00 +0000 Trajectory control for a Hexacopter UAV using Nonsingular Terminal Sliding Mode Control <p>Research and development in the field of UAVs have witnessed a significant surge lately. This study aims to design a control strategy for tracking the trajectory of unmanned aerial vehicles (UAV) Hexacopter based on sliding mode control theory. First, the non-linear translational and rotational mathematical model of the Hexacopter is initially derived using the Newton-Euler formulation. Subsequently, a nonsingular fast terminal sliding mode controller (NSTSMC) is developed to enable the system to accurately follow the given flight trajectory, while accounting for variations in the three orientation angles.&nbsp;&nbsp; For that, six sliding manifolds are designed to have a fast dynamic response, and their stability analysis is verified using the Lyapunov direct method. To enhance the robustness of the flight controller and the control quality, external disturbances are taken into account in the modeling and control development, and chattering reduction is also taken into account. The proposed control's validity and performance are evaluated in MATLAB/Simulink compared to the classical PID controller. The comparative simulation results indicated that the aircraft under the NSTSMC could effectively flow along the predetermined trajectory, and counteract disturbances that had a negligible impact on the path without requiring undue exertion.</p> Said Khoudiri, Abdelkader Khoudiri, Belgacem Toual, Mohamed Khaleel Copyright (c) 2024 Fri, 05 Apr 2024 00:00:00 +0000 Real-time of a two-level three-phase inverter controlled by PWM and full wave techniques <p>Sustainability in power generation is readily available and must be able to adapt to a variety of energy needs or integrate seamlessly into alternative distribution networks. This research aims to bridge the gap between continuous energy production and efficient energy utilization by advancing the understanding and application of three-phase dual-level voltage inverters. This study focuses on two main objectives: firstly, to develop a comprehensive model and secondly, to validate the functionality of a three-phase two-level voltage inverter. The control strategy employed for this inverter involves the full-wave method and pulse-width modulation (PWM). The results obtained from the hardware implementation of these control methods show impressive levels of success, closely matching the expected performance of the three-phase inverter. This success underlines the robustness and effectiveness of both full-wave and PWM control strategies. To further underline their practical applicability, experimental validation of PWM and Full Wave control methods is demonstrated in a controlled research laboratory environment.</p> Noureddine Nekbil, Yacine Guettaf, Mohamed Boudiaf, Mohamed Nour Copyright (c) 2024 Fri, 05 Apr 2024 00:00:00 +0000 PSO-enhanced discrete-time integrated sliding mode-based control of three-level NPC converter for grid-connected PV-FC distributed generation system <p>This study proposes the control of a three-level NPC converter applied in a PV-FC hybrid generation system based on discrete-time integral sliding mode control (DISMC) combined with the particle swarm optimization (PSO) technique. First, the comprehensive depiction and modeling of the system's main components are initially presented. Then, the controller's detailed design procedure is given.&nbsp; The sliding manifold is designed to have a fast dynamic response, and its stability analysis is verified using the Lyapunov direct method. Next, the optimization procedure is introduced to calculate the optimal values of the DISMC gains. Furthermore, a power management strategy is examined within the proposed control system to maximize the utility of the power produced by the hybrid system; the control is done through the designed PSO-DISMC to allow decoupled control of the active and reactive powers in two distinct modes of operation (the feeder-flow control (FFC) and the unit-power control (UPC) modes). The simulation of the approach is conducted in MATLAB/Simulink, and the findings demonstrate the effectiveness and robustness of the proposed control strategy.</p> Abdelkader Khoudiri, Said Khoudiri, Mohamed Khaleel Copyright (c) 2024 Fri, 05 Apr 2024 00:00:00 +0000 On the existence of positive solutions of some nonlocal elliptic problems involving fractional p–Laplacian operator <p>Our aim in this paper is to analyze the existence of solutions to a nonlocal elliptic problem involving the fractional Laplacian operator. These operators are utilized to solve an equation defined within a bounded domain &nbsp;in . The operator &nbsp;is a fractional Laplacian , where &nbsp;with the condition &nbsp;and &nbsp;is a non-negative function almost everywhere with respect to the variable , and &nbsp;are real numbers. The article establishes two existence theorems for weak solutions using Tychonoff and Schauder fixed-point theorems. These theorems are formulated based on different hypotheses regarding the parameters and .</p> Omar Djidel, Med-Salem Rezaoui Copyright (c) 2024 Mon, 08 Apr 2024 00:00:00 +0000 Numerical investigation of granular column-improved soils using the direct shear test <p>The granular columns treatment is widely used in the weak soils. The present paper focuses on the numerical modeling of a direct shear test on granular columns in soils. The finite difference code Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) was used in this research work, to evaluate the equivalent properties of granular column-improved soils with different diameters of the columns, and different plan configurations. The results of these numerical tests are discussed in terms of increases the shear load-strength and decreases the horizontal displacement due to the variation of arrangements, Young's modulus and the friction angle of the granular columns. Different types of failures observed in the granular columns. Bending failure mode is the main in the granular column with large values of Young's modulus and the friction angle when subjected a lateral load.</p> Mohamed Labed, Naas Allout, Abdelhak Mabrouki Copyright (c) 2024 Mon, 08 Apr 2024 00:00:00 +0000 Eddy current nondestructive evaluation of metallic plates electrical conductivity using artificial neural networks based inverse problem <p>The most used method and extensively studied in the literature for conductors’ characterization is Eddy Current Nondestructive Evaluation (ECNDE) due to its significant advantages, such as its ability to preserve the integrity of the structures or materials to be examined during manufacturing or a regular in-service nondestructive testing. Various approaches are developed for the Eddy Current measurement of the electrical conductivity. In the present work, the evaluation of the electrical conductivity is treated as an inverse problem. In pursuit of this aim, a combination is established between Eddy currents evaluation and artificial neural networks (ANN) to evaluate the electrical conductivity of homogeneous metallic plates from eddy-current probe impedance measurements. For this purpose, an experimental setup is developed, including a bobbin-coil probe, metallic plates (target), data acquisition and signal processing systems. Finally, experimental conductivity values of various metallic plates using ANN are compared with those obtained using four-point measurements of direct current potential drop (DCPD) made on the same plates and very good agreement is obtained.</p> Abdelkader Bouhlal, Nasreddine Nait-Said, Fatima-Zohra Louai, Said Touati Copyright (c) 2024 Tue, 09 Apr 2024 00:00:00 +0000 Long-term solar radiation forecasting based on LSTM and attention mechanism: a case study in Algeria <p>The growing adoption of photovoltaic (PV) energy in urban areas underscores its capability to meet energy demands effectively. The accurate forecasting of meteorological parameters, particularly global solar radiation, is paramount for the efficient management and utilization of solar energy resources. Solar radiation forecasting methods typically fall into two main categories: cloud imagery combined with physical approaches, and Artificial Intelligence (AI) based methods. Due to the non-stationary nature of solar radiation and the high nonlinearity of atmospheric conditions, conventional forecasting approaches often exhibit poor accuracy. Artificial intelligence based approaches, such as machine learning and deep learning algorithms, are extensively employed in global solar radiation forecasting research, demonstrating impressive accuracy.&nbsp; In this respect, this paper presents a novel approach for long term monthly forecasting of global solar radiation using a Bidirectional Long Short-Term Memory (LSTM) architecture augmented with an attention mechanism that includes a Squeeze and Excitation (SE) block (SE-BiLSTM). The effectiveness of this model is extensively evaluated for long-term monthly solar radiation forecasting using meteorological data collected over a 20-year period (from Jan 2001 to Dec 2020) from the National Aeronautics and Space Administration (NASA). The proposed SE-BiLSTM model is compared with well-established forecasting models including Naïve, Autoregressive Moving Average (ARMA), Multi-layer Perceptron (MLP), LSTM, and Bidirectional LSTM. Through rigorous simulation tests, our model demonstrates superior performance, achieving the lowest mean absolute percentage error (MAPE) of 4.52% and mean absolute error (MAE) of 7.89 kW/m<sup>2</sup>. This advancement holds significant promise for enhancing solar energy forecasting accuracy and its practical application in renewable energy systems.</p> Ali Teta, Maissa Medkour, Abdelaziz Rabehi, Belkacem Korich, Derradji Bakria Copyright (c) 2024 Mon, 15 Apr 2024 00:00:00 +0000 Enhancing passive cell balancing techniques for electric vehicles <p class="referencias">This research endeavors to enhance the efficiency and functionality of electric vehicle (EV) energy storage systems by scrutinizing the state of charge (SOC) across three batteries. Utilizing Matlab Simulink, a comprehensive battery management system (BMS) integrating passive cell balancing techniques has been meticulously devised. Additionally, a pioneering protective mechanism has been proposed to prevent undue discharges and overcharges, thus ensuring the longevity and reliability of EV battery systems. The study's findings underline the significance and applicability of the developed model in facilitating prospective enhancements within the realm of EV energy storage systems. By meticulously analyzing SOC dynamics across multiple batteries, the study offers valuable insights into optimizing battery utilization, prolonging battery lifespan, and enhancing overall system performance. Moreover, the integration of passive cell balancing techniques within the BMS framework represents a noteworthy advancement in battery management strategies. This approach not only promotes uniformity in SOC distribution among battery cells but also minimizes energy losses and mitigates the risk of cell degradation, thereby bolstering the operational efficiency and durability of EV energy storage systems. Furthermore, the proposed protective mechanism serves as a proactive measure to safeguard against potential damage caused by extreme operating conditions, such as overdischarge and overcharge events. By implementing real-time monitoring and control mechanisms, the protective system ensures the safe and reliable operation of EV batteries under varying driving conditions, thereby enhancing both safety and performance aspects. In conclusion, this research contributes to the ongoing efforts aimed at advancing the state-of-the-art in EV energy storage systems, holding immense potential for fostering innovation and driving sustainable progress in the field of electric mobility.</p> Rachad Moumni, Idriss Benlaloui, Kouider Laroussi, Nadir Benalia Copyright (c) 2024 Mon, 15 Apr 2024 00:00:00 +0000 Influence of the recycled sand on the cement mortars <p>In construction, a recent direction is to examine and integrate alternative sources of building materials with the goal of substituting the use of natural materials. This transition is encouraged by growing concern among policymakers and researchers regarding the environmental footprint of the construction industry. The incorporation of recycled aggregates into cementitious materials, such as concrete or mortar, results in a deterioration of their mechanical performance and their durability. Scientific studies devoted to recycled concrete have demonstrated that it is affected by the introduction of these recycled aggregates, in particular by the use of recycled sand. The latter is characterized by the presence of significant proportions of hardened cement, particularly that coming from a recycling plant. In this work, we aim to study experimentally the influence of the nature of recycled sand on the properties of cement mortars, substituting natural sand, with different percentages by volume: 0, 15, 30, 40, 50 and 75 %, by two types of recycled sand, one from the crushing of structural concrete and the other from a recycling plant. The mortar mixtures were made from CEM I 52.5 and Sand/Cement ratio = 3. The plasticity of these mortars was kept constant and the recycled sands have been pre-wetted. The comparative study between the different compositions of recycled mortars has shown that the physical and mechanical properties are influenced by the incorporation rate of the recycled sand. Of which, increases in the compressive strengths of recycled mortars were recorded, particularly those based on sand from the crushing of structural concrete, compared to the control mortar based on natural river sand. However, the flexural strengths of the recycled mortars suffered a slight reduction compared to the reference mortar.</p> Berredjem Layachi , Bordjiba Abdelhak, Molez Laurent , Arabi Nourredine Copyright (c) 2024 Mon, 15 Apr 2024 00:00:00 +0000 Control and fault diagnosis for two-interleaved boost converter associated with to PEMFC <p>This paper presents an enhanced control and fast fault detection method, localisation and isolisation for a two-phase interleaved boost DC/DC converter specifically designed for fuel cell applications. Fuel cells are known for their rapidly changing output voltage and current due to fluctuating load demands. Conventional converters might not be able to respond fast enough to maintain stable operation under such conditions.The two-phase interleaved design offers significant advantages. such as reduced ripple current delivered by dividing the Input current, the converter significantly lowers input and current ripple compared to single-phase designs. Each phase handles a smaller portion (1/N) of the total current, leading to reduced stress on individual components and enhanced reliability and operating margins. Additionally, Interleaving minimizes conduction losses by dividing the current among multiple converter stages. This work presents a model of a two-phase interleaved boost DC/DC converter and implements a PI controller for its output voltage regulation. This control method guarantees good performance even under varying reference voltages and load conditions. The proposed algorithm addresses the challenge of open circuit switch failures by utilizing current slopes for swift fault detection and rapid corrective action. This ensures accurate reference tracking, desired dynamic response, and timely fault detection and localization. The entire system was rigorously tested using MATLAB/Simulink software under various conditions, including reference voltage and load variations, as well as open circuit switch faults. The results showcase the proposed system's superior performance in terms of: Dynamic performance: The system exhibits rapid response to changes in operating conditions. Fast fault detection, localization and isolation.</p> Abdesselam Belkheir, Benaissa Amar, Bouchhida Ouahid, Meradi Samir, Benkhoris Mohamed Fouad Copyright (c) 2024 Mon, 15 Apr 2024 00:00:00 +0000 Interior point algorithm for second-order cone optimization based on a new kernel function <p>Second-order cone optimization (SOCO) problems are crucial in various fields such as engineering, finance, and machine learning due to their ability to model complex convex optimization tasks efficiently. In this article, we propose an interior point algorithm tailored for SOCO, leveraging a novel kernel function to enhance optimization performance. Traditional interior point methods for SOCO often encounter challenges in scalability and efficiency, particularly with large-scale problems. These methods typically rely on barrier functions that may suffer from slow convergence rates, especially when dealing with highly ill-conditioned or degenerate cones. To address these limitations, our approach introduces a new kernel function that exploits the geometric properties of second-order cones, thereby improving convergence behavior and computational efficiency. The key innovation of our algorithm lies in the construction of the kernel function, which incorporates insights from the structure of second-order cones to efficiently capture the curvature information of the optimization problem. By exploiting this curvature information, our algorithm can effectively navigate the optimization landscape, leading to faster convergence and enhanced robustness compared to traditional methods. Furthermore, our algorithm is equipped with advanced techniques for handling various challenges encountered in SOCO, such as dealing with degenerate cones and exploiting problem structure to accelerate convergence. Additionally, we incorporate strategies for warm-starting and adaptive step-size selection to further improve efficiency, particularly in iterative optimization processes. Finally, our proposed interior point algorithm for second-order cone optimization, based on a new kernel function, derives the iteration bounds <em>O</em> (<em>Nlog</em> (<em>N</em>/∊)) for large update methods. Here denotes <em>N</em> the number of second-order cones in the problem formulation and ∊ the desired accuracy. These iteration bounds are currently the best known bounds for such methods.</p> Roumaissa Charif, El Amir Djeffal Copyright (c) 2024 Tue, 16 Apr 2024 00:00:00 +0000 A Review of electricity tariffs and enabling solutions to optimize energy billing at the university centre of Tipaza, Algeria <p>The subject of our study follows the guidelines of our Minister for Higher Education and Scientific Research, who promotes bringing universities closer to the user sector. This document addresses the need to optimize the use of electricity in order to reduce energy bills, highlighting the case of the Morsli Abdellah university center in Tipaza (ARGELIA), which has faced a significant increase in its electricity costs in recent years. To tackle this problem, the center's professors and specialists are carrying out numerous scientific investigations aimed at finding applied solutions to reduce energy expenditure in order to improve the budget situation. First, we collected information on electricity consumption. Then we proceeded to establish a balance of power that allowed us to target potential sources of energy savings. Then, energy efficiency solutions. The main objective of the study is to optimize the use of electricity within the center, thereby reducing costs. The analysis of historical consumption data guides the implementation of specific strategies, including the choice of optimal prices and power analysis. The study brings significant results, recommending tariff readjustments, a reduction in available power and the installation of reactive energy compensation devices. The study recommends strategic changes to correct inefficiencies, such as changing prices, reducing available power and installing reactive compensation devices. The results suggest notable savings by eliminating costs associated with reactive energy and aligning the energy bill with actual consumption. These specific actions demonstrate the possibility of significantly optimizing energy management in an institutional context, with financial and ecological benefits.</p> Djamel Eddine Tourqui, Mohamed Bey, Rostom Khalef Copyright (c) 2024 Wed, 17 Apr 2024 00:00:00 +0000 Patologia e reabilitação de alvenarias argamassadas: estudo de caso <p>O presente estudo investiga manifestações patológicas em revestimentos argamassados de alvenarias em Goiânia, Goiás. Foi adotado como estudo de caso uma habitação térrea, onde foram feitas as inspeções e também as correções das patologias encontradas. Destaca-se a falta de projetos específicos como causa principal das patologias. A causa mais frequente encontrada foi a ausência de detalhes técnicos, como o traço adequado da argamassa e as juntas de dilatação, é um desafio significativo. Como solução preventiva, esse estudo vai apontar como melhoria técnica a substituição da cal por aditivos plastificantes na argamassa e aplicação de impermeabilizantes e seladores acrílicos nas fachadas. Isso evita patologias e melhora o conforto térmico, criando ambientes saudáveis. Destaca-se a relação entre as medidas preventivas e o bem-estar dos ocupantes das edificações. Além de evitar patologias, a aplicação dessas medidas contribui para a criação de ambientes mais saudáveis e confortáveis. A abordagem preventiva é fundamental para a construção civil, visando à qualidade e à durabilidade dos revestimentos argamassados. A implementação de medidas de aprimoramento de procedimentos e materiais de construção civil contribui não apenas para a satisfação dos usuários das edificações, mas também para a preservação do meio ambiente e a economia a longo prazo. Este trabalho destaca a importância das práticas preventivas na construção civil tanto em Goiânia como em outras regiões. Suas conclusões oferecem orientações valiosas para profissionais do setor, incentivando o aprimoramento constante das técnicas construtivas. O conhecimento gerado por esta pesquisa pode servir como base para o desenvolvimento de projetos mais eficientes, sustentáveis e capazes de proporcionar ambientes seguros e confortáveis para todos.</p> Raissa Garcia Evangelista Montes, José Coimbra Copyright (c) 2024 Thu, 18 Apr 2024 00:00:00 +0000 Optimizing PMSM performance by integrating predictive current, speed and sliding mode flux weakening controllers <p class="referencias">To improve the control performances of permanent magnet synchronous motors (PMSMs), this paper combines the sliding mode controller (SMC) and model predictive controller (MPC) to balance the contradictions between stability and dynamic performance, reduce current and torque ripples, and provide precise, complete current and speed control. At first, the MPC is employed to control the current and speed of motors, which could solve the chattering issue of the traditional sliding mode control method and effectively guarantee the stability of the control system. Second, a sliding mode observer (SMO) is incorporated to eliminate the interference of flux variation and then reduce the current and torque ripples. Meanwhile, the sliding mode controller is used to adjust the speed of motors and generate an adjustable switching surface to implement rapid and accurate control of the motor. This paper presents the design and realization process of each controller in detail, respectively shows the design principle of the combined controller and verifies the control effect of the combined controller under different motor speeds through simulation, and analyzes the control advantages and its application. The simulation results prove that the combined controller reduces the current and torque ripples to a certain extent in speed regulation, and the control performance is more stable and robust over a wide range of speed. In addition, this paper discusses the practical application of combined controllers in industrial and electric vehicle motor control in the later stages and presents the influence and significance of combined controllers on the efficiency and stability of PMSM control. From the perspective of application and system integration, the integrated design of SMC, SMO, and MPC can further promote the development of high-performance PMSM in the industrial and automotive industries in the future.</p> Fadi Mohamed Kethiri, Omar Charrouf Copyright (c) 2024 Thu, 18 Apr 2024 00:00:00 +0000 Characterisation of lightweight concrete blocks made from dune sand and wood chips <p>Lightweight concrete blocks are often used in house construction. Over two millennia have passed since lightweight concrete was first developed, and advancements in technology are continuously being made. Because lightweight concrete has a lower density than regular concrete, using it helps reduce the weight of the components it is used to build and, in turn, the dimensions of the load-bearing components. This lowers the forces that the foundations transmit to the ground and, in turn, the dimensions of the latter, allowing construction on low-bearing soils. This paper presents the results of an examination into the composition and properties of lightweight concrete made with dune sand and wood chips. The studied composite is a sand concrete lightened by adding wood ships. Following this composition, we made several samples of lightweight concrete. Using laboratory tests, we have determined some of the physical and mechanical characteristics of these lightweight concrete samples. The results showed that the characteristics of this new wood concrete composite are close to French recommendations in terms of compressive strength. Thermal insulation is significantly improved, but sound insulation is not yet competitive in terms of attenuation.On the basis of the results obtained, these agglomerates can be used to build light, load-bearing, insulating walls. The results of the characterization provide valuable insights into the potential applications and performance of lightweight concrete blocks made from dune sand and wood chips.&nbsp; The findings contribute to sustainable construction practices by exploring eco-friendly alternatives and expanding the knowledge base in the field of lightweight concrete block production.</p> Laid Guermiti, Abdelhalim Bensaada, Mustapha Rabehi , Mohamed Tahar Bentebba, Tayeb Bouziani Copyright (c) 2024 Thu, 18 Apr 2024 00:00:00 +0000 DNA sequences for robust encryption: a strategy for IoT security enhancement <p>As the Internet of Things (IoT) permeates our lives, connecting everything from household appliances to complex industrial systems, the imperative to secure these devices intensifies. Cryptography, as a cornerstone of digital security, plays a crucial role in safeguarding transmission channels from intrusions and misuse. Cryptography secures communications and data within IoT networks by ensuring three key functions: confidentiality, integrity, and authentication. DNA-based cryptography emerges as a promising innovation in the field of cybersecurity, particularly for the Internet of Things (IoT), where data and communication security is an escalating concern. Utilizing the unique properties of DNA, such as its massive storage capacity and biomolecular complexity, this approach introduces a novel dimension of security. This study introduces a balanced approach within DNA cryptography to enhance message security in Internet of Things (IoT) settings. It outlines a method for creating secure symmetric keys using DNA sequences, typically derived from human chromosomes, and then applies biological techniques like transcription and a biological Xor operation. This step is succeeded by a translation phase that utilizes an index table created from an initial key, making the process more complex.</p> Kadda Benyahia, Abdelkader Khobzaoui, Soumia Benbakreti Copyright (c) 2024 Mon, 22 Apr 2024 00:00:00 +0000 Robust fuzzy – backstepping mode control of an induction motor <p>This paper presents a novel control for induction motors using backstepping control and fuzzy logic. The Backstepping control is suggested as a substitute for the conventional PI controller to attain high-performance motion control systems for the speed, flux, and current control loops. Stability analysis, based on Lyapunov theory, is also conducted to guarantee the convergence of the speed tracking error from all possible initial conditions. The speed regulator was changed to a fuzzy logic regulator. The simulation results confirm that the proposed hybrid control fuzzy-backstepping scheme offers improved performance in terms of trajectory tracking ability and robustness against variation when subjected to time-varying reference input.</p> Abdelghafour Herizi, Abdelhafid Benyounes, Riyadh Rouabhi, Abdelghafour Boudras, Fayssal Ouagueni, Abderrahim Zemmit Copyright (c) 2024 Mon, 22 Apr 2024 00:00:00 +0000 Combined impact of dune sand and crushed brick waste on the characteristics of raw earth bricks <p>The primary motivators behind the renewed focus on employing locally available materials, recycling industrial waste, and utilizing their characteristics for adobe bricks are cost-effective building materials, thermally efficient, consuming less energy and reducing environmental emissions. In light of this, this study examines how the physical characteristics and mechanical behavior of quicklime-stabilized adobe bricks' are affected when dune sand (DS) and crushed fired brick waste (CB) are combined. The thermal conductivity of adobe bricks was also studied. According to the data, the compressive and flexural strengths significantly improved with the addition of 40% CB. A slight strength increase was observed with the incorporation of 20% DS, which is not the case for the other types of sand. Addition of 20% DS to the mixtures resulted in a decrease in the TA and Cb. SEM technique confirmed that the use of CB and DS in the adobe bricks preparation procedure resulted in a reduction of voids in the matrix, thereby improving the characteristics, especially their physical characteristics. Additionally, there was an improvement in the apparent density when the M1 combination was included. This resulted in an increase in the speed at which ultrasonic waves propagated. Similarly, M3 combination helped to reduce the TA and Cb. With regard to M1 combination, it increased the compressive and flexural strength of adobe bricks by 71.75% and 52.23%, respectively, as compared to the RB. Significant increases in elasticity modulus were observed in compression and flexion. The combination of CB and DS slightly increased the thermal conductivity.</p> Ferdous Bezaou, Ouarda Izemmouren, Salim Guettala Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 25 Apr 2024 00:00:00 +0000 Numerical modeling of the stress-strain behavior of a viscoelastic material in a 2D model by FEM <p>Numerical modeling of behavior plays an important role in knowing the changes to be made and in optimizing simulation results. Currently, modeling occupies a very necessary place in modern industry for the life study of any problem. This paper deals numerically with the variation and relationship between stress and strain for a model of tensile behavior. In addition, the study is based on the one hand on the number of holes in a plate, and on the other hand by the increase in the tensile load 10, 20 and 30N. The FEM finite element method was used. Additionally, the viscoelastic material was applied. In addition, the parametric mesh has square elements of type (CPS4) bilinear plane stress quadrilaterals, with 4 nodes were used. However, can contribute to a better understanding of the problem of guiding by different numbers of holes concerning viscoelastic behavior for an epoxy material. In addition, this study allows us to know which model is the most resistant during tightening. The results of the final element method (FEM) numerical model were compared, after application of different loadings, to determine the deformation and stress resulting from these loadings, particularly at the holes. On the other hand, the study showed that there is a relationship between viscosity and stress, and a relationship between deformation and stress according to Hooke's law. The variation and the relationship between the stress-strain is then modeled using the finite element calculation code ABAQUS. In addition, the results obtained concerning the numerical simulation were compared and discussed between the different case studies. A good correspondence was obtained between the different comparison results in all the modeling cases of our work.</p> Mohammed Bentahar, Moulai Arbi Youcef, Noureddine Mahmoudi, Habib Benzaama Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Fri, 26 Apr 2024 00:00:00 +0000 Experimental study of the mechanical and optical properties of glass-polyester fiber composite based on response surface methodology <p>Due to the intricate amalgamation of various components, composite materials boast mechanical properties that surpass those of their constituents. Among these composite materials, glass fiber-reinforced polyester composites emerge as prominent contenders, finding extensive utility, especially in agricultural greenhouse construction. These structures garner significant acclaim for their exceptional ability to withstand adverse weather conditions, ensure prolonged durability, and transmit light efficiently, thus creating optimal growing conditions. Consequently, they have become the favored choice among farmers seeking dependable and sustainable environments for cultivation. Within the scope of this study, we employ Response Surface Methodology (RSM) as a comprehensive tool to delve deeply into the mechanical and optical characteristics inherent in such composite materials. Our investigation is meticulously tailored to unravel the intricate interplay among crucial factors such as fiber content, length, and plate thickness, elucidating their direct impacts on mechanical properties like stress and elasticity modulus. Our rigorous examination reveals that the pinnacle of mechanical performance is attained within a specific range: fiber content ranging from 20% to 40%, fiber lengths spanning 35 to 45 mm, and plate thicknesses measuring between 0.6 to 3 mm. Furthermore, our meticulous analysis of transmittance measurements uncovers an intriguing correlation: thinner thicknesses and lower fiber content correspond with heightened light transmission across the visible spectrum. Conversely, elevating the fiber content or thickness enhances mechanical robustness but concurrently diminishes light transmittance. Thus, achieving a harmonious equilibrium among these attributes becomes imperative for the pragmatic construction of agricultural greenhouses. Additionally, we venture into incorporating ultraviolet (UV) plastic films to augment the optical prowess of these composites, further elevating their efficacy in greenhouse applications. By embarking on this comprehensive investigation, our overarching objective is to propel sustainable farming practices forward by furnishing a nuanced understanding of the multifaceted factors that shape the performance of glass fiber-polyester composites in agricultural greenhouse applications.</p> Djamila Mokhtar, Malika Medjahdi, Noureddine Benderdouche, Mohammed Amin Chemrak, Belaid Mechab, Benaouda Bestani, Dominique Baillis Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 29 Apr 2024 00:00:00 +0000 Active and passive soil wedges influence on the natural frequency of retaining structures <p>Studying the behavior of retaining structures has been very important issue due to their large application in civil engineering. An accurate determination of the earth pressure and the natural frequency is elemental for studying the dynamic behavior of these structures. In the most previous investigations, the soil backfill was considered sufficient width as rectangular mass whereas in the real. the backfill behind retaining structures repartitioned as triangular active and passive soil wedges. Rectifying this weakness, this study proposed an analytical model for calculating the natural frequency of retaining structures by considering the triangular active and passive soil failure wedges, which take into account the variation of earth pressure behind retaining structures. The soil wedge causes an increase in the value of natural frequency. It is clarified that the soil wedge has a large influence on the natural frequency of retaining structures. In this regard, the consideration of active and passive soil wedges behind retaining structures plays an important influence in determining of the natural frequency.</p> Guechi Lyazid, Bordjiba Abdelhak Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 29 Apr 2024 00:00:00 +0000 Predicting the compressive strength of ecological concrete made with PET granules using artificial neural networks (MATLAB) <p>The problem of getting rid of waste, especially plastic waste, has become a problem that worries governments. From this standpoint, the method of getting rid of plastic appeared by inserting it and making it one of the components of concrete, and it became called environmentally friendly concrete.The purpose of this research is to evaluate the performance of long-lasting concrete that has partial volumetric substitution of aggregate with polyethylene terephthalate (PET) granules. mechanical characteristics, such as tensile and compressive strength, This work offers a prediction model-based method for predicting the compressive and tensile strength of environmentally friendly concrete with various kinds of plastic aggregates (PET) using artificial neural networks (ANN). Artificial neurons, which resemble brain neurons in general, are linked units or nodes that make up an ANN. These are linked together by edges that resemble brain synapses. Connected neurons send messages to an artificial neuron. Previous literature collected a data group with five affecting characteristics: water, fine aggregates, cement, coarse aggregates, PET aggregates, and model validation. Tensile and compressive strength were the outcomes. Additionally, a sensitivity analysis was done to confirm the stability and robustness of this model. The testing results demonstrated the excellent performance of the ANN model, which makes it a viable method for predicting the compressive and tensile strength of an environmentally friendly concrete. In addition, the correlation coefficient for compressive strength was found to be 0.9999, and tensile strength is 0.9999 which indicates the high reliability of the model used in the analysis and the accuracy of the results obtained.</p> Houcine Bentegri, Mohamed Rabehi, Samir Kherfane Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 29 Apr 2024 00:00:00 +0000 Mega-train turbine performance improvement through intake air cooling system dimensioning and design <p>Gas turbines are a well-known rotating machines used in a variety of industrial sectors. However, the aforementioned turbines are highly sensitive to climatic changes such as variations in temperature and humidity, which can significantly affect their performance. Focusing on the being cited limitations, and aiming at the improvement of the system performances, it is important to control the ambient air temperature. In this context, the current study analyzes the design of an enhanced air-cooling system by putting forth a novel and practical method for raising output while lowering investment costs and ensuring steady and dependable operation. Firstly, the thermodynamic analysis of the realistic MS-7001 is carried out. Then, the feasibility of an air-cooling system for the MS-7001 turbine used at the Natural Gas Liquefaction complex – Skikda is conducted before starting the prototyping process. The proposed system uses a water evaporative cooler as a pre-cooler to reduce the temperature by around 12°C, while, increasing the relative humidity to around 90%, In order to ensure the thermal effectiveness of the system, a compressed air injection station is used for the production of a cold air at high pressure. CFD analysis results and conducted experiments on the proposed prototype have confirmed that it is effective and can be adapted to both wet and dry climates, even under hard variations. The adopted technique enhances the system efficiency and makes it possible to maintain the nominal operating point of gas turbines independently of external variations of atmospheric condition, without modifying their composition, which minimizes investment, development and maintenance costs.</p> Mohamed Djennane, Lina Benyoucef, Houda Yakoub, Rachid Benbouta, Seif Eddine Chehaidia Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 29 Apr 2024 00:00:00 +0000 Comparative study between sliding mode and DTC of doubly fed induction machine <p>Although the great advance in term of AC machine construction, control strategies are also necessary to be developed and improved continuously satisfying output torque/power. Hence the Doubly fed induction motor (DFIM)is widely used in industry, since it can operates in wide range of speed variation around the synchronous speed and the control of flux and torque is independent. In this paper, control of doubly fed induction motor (DFIM) has been investigated, which two control strategies have been studied and compared: the first strategy uses a sliding mode control (SMC); the second employs Direct Torque Control (DTC). Modeling of DFIM and details of both control strategies have been presented. the mathematical description of different basic dynamic models of the DFIM have been carried out The performances in terms of torque tracking, accuracy and robustness of both control techniques under normal and various speed and load conditions have been demonstrated and compared.</p> Abderrahim Zemmit, Khaled Belhouchet, Sabir Messalti, Abdelghafour Herizi Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 29 Apr 2024 00:00:00 +0000 Flow of Bingham fluid through a three dimensional thin layer <p>The paper is devoted to the study of asymptotic behavior of the solution of three dimensional steady flow of Bingham fluid through a three dimensional thin layer with Dirichlet boundary conditions. We are interested in the asymptotic behavior, to this aim we prove some convergence results concerning the velocity and pressure when the thickness tends to zero. The limit problem obtained after transforming the original problem into one posed over a fixed reference domain and the parameter representing the thickness of the layer tend to zero is studied. The lower-dimensional constitutive law and the differential equation satisfied by the limit variables in the non rigid zone are obtained. In addition, the uniqueness of limit solution has been also established. Existence and uniqueness results and a lower-dimensional constitutive law are obtained. An identical study of a two-dimensional problem yields a one dimensional model prevalent in engineering literature.</p> Salim Saf, Farid Messelmi Copyright (c) 2024 Mon, 29 Apr 2024 00:00:00 +0000 Examining electrical equivalent circuit models of insulators in transmission lines under pollution conditions: a comprehensive study and analysis <p>This research presents a comprehensive study investigating the behavior of insulators in transmission lines under various pollution conditions. Utilizing equivalent electrical circuits, the analysis aims to understand the impact of pollution on insulator performance, which is crucial for maintaining the reliability and efficiency of power transmission systems. By providing valuable insights into the relationship between pollution and insulator behavior, this study contributes to the development of improved strategies for mitigating the effects of pollution on transmission lines, ultimately enhancing the overall safety and stability of electrical power networks. The study focuses on a digital model that enables the visualization of potential and electric field distribution within a series of glass insulators utilized in Algerian electrical grids. Initially, a parallel RC network equivalent circuit was devised and its parameters were determined through finite element analysis using Comsol Multiphysics. This equivalent circuit was subsequently integrated into ATP/EMTP software to simulate leakage currents, yielding satisfactory outcomes. The model was then incorporated into the isolator's equivalent circuit. Results from various simulations indicate that the occurrence of discharge along the dry strip impacts leakage current. Furthermore, the re-initiation of discharge on the contaminated insulator's surface is influenced by the pollutant deposit's conductivity and distribution. Therefore, understanding the pollution level is vital for accurately evaluating and sizing the insulator chain at the installation site.</p> Khaled Belhouchet, Abderrahim Zemmit, Lyamine Ouchen, Abdelhafid Bayadi Copyright (c) 2024 Mon, 29 Apr 2024 00:00:00 +0000 Existence of a periodic solution for a state-dependent delay differential equation with a singular perturbation <p>The idea of this article came from the works dones by Khung and Smith on the one hand in [2] for &nbsp;and Arino and Al in [1] for &nbsp;on the other hand, to proves the existence of a slowly oxillating preriodic solution by the fixed point theorem of Picard. I proposed the following question: Do the result remain valid if &nbsp;1 ? by the same method with using the homotopy well defined link between the application of Khung and Smith and the application of Arino and &nbsp;and indeed, I came to prove existence of a slowly oxillating preriodic solution by the fixed point theorem of Picard, therefore the result obtained in this work is generalization of two special cases. A State-dependent Delay Differential equation play important role in recent years to modeling of several phenomenon, in dynamics of populations, in biology and even in the social life for example: When we take our driving test, we learn that the reaction time of our nervous system when driving is of the order of a few seconds, and that we must take care to maintain a sufficient distance between two cars following each other, from this example, we notice that the delay can be useful. Although this work has added a new addition to the scientific field which is a generalization and linking between two special cases, it remains somewhat limited because it takes special case of Arino and Al. Therefore in the futur, we are thinking about a new work that takes into account the general case of Arino and .</p> Mohamed Nehari Copyright (c) 2024 Mon, 29 Apr 2024 00:00:00 +0000 The geometry uniformity parameters effect on the dynamic behaviour of trapezoidal beam <p>Understanding the delicate interplay between geometric design principles and dynamic responses is vital for numerous engineering applications because it allows optimization of structural integrity and performance for manufacturing and special use of this structures. In this study, a complete numerical analysis is undertaken to investigate how differences in geometric parameters impact the structural behaviour of a cantilever smart trapezoidal beam, giving useful insights for engineering applications. The beam consists of a host structure made of aluminum couple with two piezoelectric layers on its top and bottom surface. For such purpose, the study a 3D finite element model has been implemented in ANSY APDL and applied by Matlab we used the interfaces between the two software, considering that the beam changes its form in the axial direction following polynomial based function. The function takes two geometric parameters as an input which are the tapering ratios and the degree of non-uniformity. The beam is then subjected to a harmonic based excitation and the effect of changing tapering ratios and the degree of non-uniformity is analyzed., allowing analysis of the effects of altering tapering ratios and the degree of non-uniformity The results led to a conclusion that just by manipulating the mentioned parameters a considerable changing in the fundamental frequency and the amplitude has been noticed. Addition our numerical analysis shows that small changes to the tapering ratios and degree of non-uniformity have a considerable influence on the behavior of cantilever smart trapezoidal beams. These discoveries add to continuing research in smart materials, paving the road for creative engineering solutions.</p> Mohamed Bouamama, Mohamed Bouamama, Zouaoui Satla, Azzeddine Belaziz, Lakhdar Boumia Copyright (c) 2024 Mon, 29 Apr 2024 00:00:00 +0000 Construction of non-stationary biorthogonal Wavelets based on cardinal Chebyshev B-spline <p>In this paper, we propose a novel method for designing non-stationary biorthogonal wavelets that leverages Bezout equations to compute wavelet filter coefficients. Our approach integrates cardinal Chebyshev B-splines of varying degrees (second, third, and fourth) as bases for constructing these wavelets, providing explicit formulations for both low-pass and high-pass filters at all levels. By employing this method, we streamline the design process, making it more efficient and accessible while accommodating diverse processing requirements. The utilization of Bezout equations offers a systematic framework for deriving wavelet filter coefficients, enhancing the reproducibility and reliability of the design process.&nbsp; This systematic approach ensures that the resulting wavelets possess desired properties such as vanishing moments, smoothness, and optimal localization. Moreover, by incorporating cardinal Chebyshev B-splines, we can effectively capture intricate signal and image features, addressing challenges encountered in traditional wavelet design methods. Our method not only simplifies the design process but also provides a comprehensive solution by explicitly formulating filters and dual filters across all levels. This comprehensive approach ensures that the resulting wavelets meet the specific demands of applications in signal and image processing, including compression, denoising, and pattern recognition. These advancements hold significant implications for various domains, including information technology, healthcare, and engineering, where efficient and reliable processing techniques are crucial. Moving forward, it is imperative to refine algorithms, assess parameter robustness, and conduct thorough empirical validations across diverse datasets and application scenarios. This will ensure the efficacy and scalability of our proposed method and pave the way for further advancements in non-stationary wavelet design and its applications. By continuously improving and validating our approach, we can foster innovation and enhance practical outcomes in a wide range of fields.</p> Yasmine Fourar, Khaled Melkemi, Mahmoud Brahimi, Abdelmalik Boussaad Copyright (c) 2024 Tue, 30 Apr 2024 00:00:00 +0000 Study of the dynamic behavior of plates in gradient properties with logarithmic and exponential porosity <p>In this paper, we are interested in the dynamic behavior of porous plates in property gradient, the property gradient material is a new generation of composite material, which is characterized by a gradual and continuous variation of physical properties, in order to attenuate the major singularity of laminar materials, which is the direct transition from one material to another. The proposed theory is based on assumption that the in-plane and transverse displacements consist of bending and shear components, in which the bending components do not contribute toward shear forces and, likewise, the shear components do not contribute toward bending moments.In order to model our plate as well as possible, we will use a high-order theory with four variables only, by injecting the exact position of the neutral surface. The originality of this work lies in the consideration of two types of porosity distribution “logarithmic and exponential” in the calculation of the position of the neutral surface.The plate is subjected to a vertical load of sinusoidal distribution expressed in double series of Fourier. The equation of motion for FG rectangular plates is obtained through Hamilton’s principle. The closed form solutions are obtained by using Navier technique, and then fundamental frequencies are found by solving the results of eigen value problems.The object of this work is to study the influence of the variation of the volume fraction, the power index and The dimension ratio on the response of&nbsp; the frequency , and ,the constraints , and and the dimensionless deflection and the dimensionless displacement obtained in the presence of porosity with logarithmic and exponential distribution compared to those uniformly distributed.</p> El Hassar Sidi Mohamed, Adem Ait Mohamed Amer, Adjoudj M’hamed Copyright (c) 2024 Tue, 30 Apr 2024 00:00:00 +0000 Impact of memory on beamforming optimization for DDPG-assisted RIS-multi-user system <p>Recently, reconfigurable intelligent surfaces (RIS) have garnered considerable attention as indispensable components driving the evolution of future 6G wireless communication systems. This heightened interest is primarily attributed to notable advancements in programmable meta-material fabrication, which enable the creation of highly versatile and adaptable surfaces. These surfaces, often referred to as intelligent reflecting arrays, represent a significant departure from the conventional capabilities of massive multiple-input multiple-output (MIMO) systems, thereby catalyzing the emergence of intelligent radio environments characterized by enhanced flexibility and efficiency. Our study is dedicated to the comprehensive exploration of coordinated design strategies that encompass both the transmission beamforming matrix at the base station and the phase shift matrix at the RIS. Leveraging recent breakthroughs in deep reinforcement learning (DRL), our approach harnesses the power of a Long Short-Term Memory (LSTM) based DRL algorithm. This algorithm orchestrates the joint design process through iterative interactions with the environment, strategically guided by predefined rewards operating within a continuous framework of states and actions. While recent research has underscored the efficacy of LSTM-based architectures in bolstering the learning capacity of reinforcement learning (RL) algorithms and simplifying the search process, our investigation reveals a nuanced insight. Contrary to prevailing trends, we find that the integration of memory into the Deep Deterministic Policy Gradient (DDPG) with LSTM (DDPG-LSTM) algorithm yields unexpected consequences, negatively impacting the system's overall performance. Through preliminary simulation results, we empirically demonstrate the adverse effect of memory on DDPG performance when applied to RIS systems. This finding not only sheds light on the complexities of optimizing 6G wireless communication systems but also underscores the importance of careful algorithmic design and parameter tuning in achieving desired outcomes in emerging technologies.</p> Naima Sofi, Faouzi Didi, Moustafa Sahnoune Chaouche, Oussama Abdelilah Sofi, Fethi Tarik Bendimerad Copyright (c) 2024 Fri, 03 May 2024 00:00:00 +0000 Experimental study on enhancing electrostatic charging of nonwoven filter media through novel electrode configurations <p style="margin: 0cm; margin-bottom: .0001pt; text-align: justify;"><span lang="ES-MX" style="font-family: 'Arial',sans-serif;">The COVID-19 pandemic has underscored the urgent need for efficient particle filtration to tackle public health challenges. This study compares the electrostatic charging capabilities of two types of electrodes: conventional Metal Lamellar Electrodes (MLE) and Modified Lamellar Plate Electrodes (MLPE) with PMMA insulation, in their role of charging nonwoven polypropylene filter media. Experimental analysis unequivocally demonstrates the superiority of MLPE in promoting effective electrostatic charge, as influenced by applied high voltage and inter-electrode distance, resulting in a significant enhancement in fine particle filtration. Numerical simulations of the electric field conducted using the COMSOL software and employing the Finite Element Method (FEM) validate these findings. FEM discretizes the domain into small finite elements and applies Laplace's equation in charge-free regions, providing a comprehensive understanding of the behavior of dual-electrode corona discharge systems. These simulations indicate higher field intensities for MLPE compared to MLE.By integrating experimental and numerical analyses, this study sheds light on the potential benefits of MLPE for air filtration systems, offering a noteworthy advancement in the control of airborne infections and reduction of environmental health risks. This research lays the groundwork for the development of more efficient and durable filtration systems, meeting the increasing demands for public health protection.The findings of this study suggest that the adoption of MLPE could significantly contribute to improving indoor air quality and mitigating the transmission of respiratory diseases. MLPE may also find utility in industrial filtration and air purification in sensitive work environments. Ultimately, this research sets the stage for the development of more efficient and sustainable filtration systems, addressing the growing needs for public health protection.</span></p> Hanane Boudra, Rafik Sayah, Abdelkader Benaissa Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 06 May 2024 00:00:00 +0000 Incorporating plastic waste fibres for sustainable sandy soil <p>The increase in urbanization has led governments to build on sites with certain geotechnical ‎hazards, such as liquefaction, ‎low bearing capacity, etc. In recent decades, as governments ‎have focused their efforts on the environmental and ‎economic aspects, researchers have ‎emphasized the need to use suitable alternative materials for the best design features, also the issue of plastic pollution is a significant global problem that requires urgent attention, current initiatives focus on the use of technical solutions to integrate non-biodegradable plastics into ‎the construction of buildings and road pavement.‎ ‎In this ‎paper, a series of direct shear tests were performed to evaluate the benefits of plastic wastes, ‎such as polypropylene ‎‎(PP) pots, and the engineering properties of sand reinforced with such ‎materials. To highlight the contribution of the ‎reinforcement to the shear strength, the ‎tests were carried out on sand reinforced with variable fibre contents (0.2, 0.4, 0.6, ‎and 0.8%) ‎for loose-density sand and medium-density sand. ‎ The experimental results showed that the increase in shear ‎strength is relatively more significant for specimens prepared with dry deposition mode as compared to those prepared ‎with wet deposition mode and it is increased with the fibre content. The inclusion of randomly distributed fibres has a significant effect on the shear strength and dilatation of sandy soils. Furthermore, the recycling fibre used in this study ‎shows a better performance in terms of shear strength. In conclusion, the use of plastic waste as ‎reinforcement would lead ‎to at least two solutions: soil reinforcement and reducing the ‎environmental impact of waste.</p> Benathmane Baghdir, Younes Abed Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 08 May 2024 00:00:00 +0000 Existance of solutions for some class of system quasilinear differentials with nonlocal boundary conditions and with nonlinearity depandant on the first derivate in time scales <p>This work is conserned with the construction of minimal and maximal solution for some equation quasilinear differentials with nonlocal boundary condition with nonlinearity is continuous function dependent on the first derivate in the time scale. In a previous study, see[11] it was found that there exists the extrimals solutions of a quasilinear elliptic system with intergral boundary conditions in the continuous case, and from here we asked the following question using the upper and lower solutions method coupled with monotone iterative technique and we asked the following question: do we have the existence of extrimals solutions for certain classes of systems of differential equations with nonlocal boundary conditions in time scales by same method. We can classify the problem following the monotonicity of the two functions and in the true types.Type 1: Increasing qasimonotonic systems.Type 2: Decreasing qasimonotonic systems. Type 3: Mexed qasimonotonic systems. In this paper we show the existence minimuls-maximuls solutions if the problem is of the type 1. If the problem is of the type 2 , we show the existence of maximuls-minimuls solutions. If the problem is of the type 3 , we show existence of least quasilear-solution. In the end, we gave examples of the results presented in this work to prove their validity through two cases: the continuous case, represented by the set of real numbers, and the discontinuous case, represented by the set of integers.</p> Mohamed Nehari, Mohammed Derhab Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 08 May 2024 00:00:00 +0000 Electronic and optical properties of MgTe quantum dots: size effect <p>The size-dependent electronic and optical properties of magnesium telluride quantum dots are investigated using a pseudopotential scheme. The emphasis is focused on the effect of the size of the quantum dots on the undertaken properties. The quantum dot radius is considered to be varying in between 1 and 10 nm. It is found that the direct- and indirect band gaps as well as the electron and hole effective masses decrease non-linearly as the quantum dot radius is increased. However, the refractive index, the static- and high frequency dielectric as well as the transverse effective charge increase as the quantum dot size is augmented. The quantum confinement is found to play a major role for the studied physical quantities as long as the quantum dot radius remains less than 5 nm. This permits to tailor the electronic and optical properties of our material according to the desired application.</p> Zouina Elbahi, Mohamed Zitouni, Ahmed Gueddim, Bachir Bentria Copyright (c) 2024 Wed, 08 May 2024 00:00:00 +0000 A numerical investigation into the equivalent parameters of a compressible soil treated by stone columns <p>A series of triaxial test simulations are adopted to estimate the equivalent strength parameters for compressible soil samples reinforced with stone columns. The simulations utilize the finite difference code, Fast Lagrangian Analysis of Continua in three dimensions <em>FLAC<sup>3D</sup></em>. An elasto-plastic model is applied to utilize a Mohr-Coulomb yield criterion. The equivalent strength parameters are estimated using newly proposed formulas for geo-composite materials. The researchers compare the obtained results to the analytical formulas proposed in the literature. Additionally, the equivalent parameters are used in equivalent area models. This study investigates the effect of the replacement area ratio. This study offers two applications. Firstly, it evaluates the safety factor of embankments constructed on compressible soil improved with stone columns. Secondly, it estimates the bearing capacity of strip footings on compressible soil treated with stone columns. In all applications, both individual column and equivalent area models are considered. The proposed equations for the equivalent elastic parameters (E, ν) and the mechanical properties, equivalent cohesion, and internal frictional angle (c and φ) give results that agree with the solutions reported in the existing literature.</p> Aissa Lahlouhi, Mohamed Labed, Mekki Mellas, Abdelhak Mabrouki Copyright (c) 2024 Thu, 09 May 2024 00:00:00 +0000 Integration of photovoltaic systems in Algeria's building electrical network: technical and financial analysis <p>This extensive study offers a thorough analysis of the complex technical and economical factors involved in incorporating photovoltaic (PV) systems into the buildings' electrical grid in Algeria. It focuses on a crucial element in the country's energy transition. This study aims to evaluate the viability and potential advantages of implementing solar panels on the rooftop of a university parking lot located at the prestigious Faculty of Electrical Engineering of the University of Sidi Bel Abbess. By utilising advanced modelling tools such as PVSOL and HOMER Pro, this study applies a comprehensive methodology to assess the feasibility of this facility. In the first step, a comprehensive three-dimensional model is carefully constructed using PVSOL software in order to assess the maximum achievable photovoltaic (PV) capacity for the neighbouring parking lot. This estimation considers several parameters, including potential shadows, size of furniture, direction, and slope. This thorough assessment establishes the foundation for subsequent examinations. Following this, a thorough technical-economic analysis is performed using HOMER Pro software to comprehensively evaluate the advantages and disadvantages of two separate scenarios: one that exclusively depends on the current electrical network and another that combines conventional grid power with solar-generated electricity. The study offers useful insights into the economic feasibility and sustainability of incorporating photovoltaic (PV) systems into the university's infrastructure, taking into account several aspects such as installation costs, maintenance requirements, electricity rates, and possible savings. The results highlight the considerable potential offered by integrating photovoltaic (PV) systems into the electrical grids of buildings, enabling the provision of electricity to both structures and perhaps facilitating the recycling of electric vehicles. Not only does this have the potential to reduce long-term energy costs, but it also plays a crucial role in promoting Algeria's shift towards more eco-friendly and sustainable energy options. This, in turn, contributes to global initiatives to address climate change and promote a more environmentally friendly future for future generations.</p> Yassine Bouroumeid, Mokhtaria Jbilou, Seyf Eddine Bechekir, Said Nemmich, Oulad Naoui Brahim El Khalil, Mostefa Brahami Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 14 May 2024 00:00:00 +0000 Optimizing solar panel orientation for enhanced power output in cloudy conditions: a case study on solar energy supply in a water treatment plant <p>This paper presents a study on optimizing the performance of a photovoltaic solar generator used to power a water treatment plant in a remote area. The research aims to evaluate the system's efficiency and focuses on determining the optimal orientation of the solar panel during periods of cloudy weather, which significantly impact sunlight availability and ozone production. To achieve this, two optimization algorithms, namely the Grey Wolf Algorithm (GWO) and the Crayfish Optimization Algorithm (COA), are employed to optimize the power output. The study is conducted in Algeria, where prevalent autumn cloud cover poses challenges for solar panel operation. By addressing these challenges and designing a high-performance photovoltaic-powered water treatment plant, the research contributes to sustainable water treatment technologies and offers promising solutions for underserved communities in need of water pumping and treatment systems. The findings highlight the importance of optimizing solar panel orientation in cloudy conditions and showcase the effectiveness of the GWO and COA algorithms in maximizing power output. By leveraging these optimization techniques, the proposed approach enhances the performance of the solar generator, ensuring efficient power production even during periods of reduced sunlight. This research not only addresses the specific case of a water treatment plant in a remote area but also has broader implications for the renewable energy sector. The study demonstrates the potential of utilizing solar energy in powering critical infrastructure, such as water treatment facilities, in areas where access to reliable electricity is limited. By fostering the adoption of sustainable energy solutions, this research contributes to the goal of achieving long-term environmental and social sustainability.</p> Elmabrouk Khelifi, Mohamed Nadjib Brahami, Imen Souhila Bousmaha, Fatima Zohra Boudjella, Mostefa Brahami, Oulad Naoui Brahim El Khalil , Seyf Eddine Bechekir, Mokhtaria Jbilou Copyright (c) 2024 Tue, 14 May 2024 00:00:00 +0000 Cement kiln dust and polypropylene fiber in expansive clay improvement <p>For civil engineers, expansive soils pose a great deal of difficulty because of their sensitivity to volume changes with different moisture levels. These difficulties are compounded by the widespread occurrence of swelling clay, which can seriously harm infrastructure, especially in arid or semi-arid areas. The geotechnical qualities of these soils have been improved through the use of various additives and techniques, resolving this problem and making the soils suitable for building. Numerous stabilization techniques, nevertheless, may have negative environmental effects. Therefore, it is imperative to investigate the use of local waste or by-products to stabilize soil in order to preserve the environment and lower stabilization costs, especially in road construction projects.To address these issues, an experiment was conducted to determine how locally obtained cement kiln dust (CKD), both alone and combined with polypropylene fibers, affected the properties of plastic clay soil, also referred to as expansive clay from Cheffia.The main objective of this study is to assess how well different CKD percentages (from 5% to 25%) stabilize soil while improving its mechanical and physical properties. The study also aims to explain how the addition of polypropylene fiber affects the unconfined compressive strength and compaction behavior of the soil in the optimal CKD-soil mixture. The results of the analysis show that the addition of cement kiln dust (CKD) significantly improved the studied soil's workability, compaction, and strength. Additionally, adding polypropylene fibers strengthens the clay's resistance to compression, which presents encouraging opportunities for reducing the difficulties brought on by expansive soils in civil engineering applications.</p> Samira Zemouli, Nadia Gouider, Zohra Melais Fatma, Innal Wissem Copyright (c) 2024 Tue, 14 May 2024 00:00:00 +0000 S-asymptotically ω-Periodic Solutions of generalized Liénard <p>The S-asymptotically ω-periodic functions are a continuous and bounded functions from the real axis to a Banach space that converges to a periodic functions as &nbsp;tends to infinity. Starting from the zero solution, we prove in this work the existence and uniqueness of S-asymptotically ω-periodic solution of generalized Liénard's differential Equation. We stady after that the regular dependence of this solution with a certain parameter in Banach space, present in our equation, and with the forcing term hwo possesses a similar nature as the later. For this, our approach will be to use a perturbation method around an equilibrium. More precisely when the forcing is a Sasymptotically ω-periodic function we study the differentiable dependence of the S-asymptotically ω-periodic solution of Liénard equation. In this study, we changed our initial objective, which was to search for na S asymptotically ω-periodic solution for our Lienard equation, a problem relating to dynamical systems, towards an approach based on functional analysis. Concretely, we adopted a strategy consisting of using the implicit function theorem on a specific operator that we defined in our workspaces. This approach allowed us to achieve the objective stated in our main theorem. To realize our aim, we use the Nemytskii operators (also called superposition operators) and state some properties on these operators. We have also extended the well-established result on the almost periodic function of the derivative of an almost periodic function to the context of S-asymptotically ω-periodic cases. Finally, and to close our work, we give a corollary which presents a particular case of our main theorem.</p> Souhila Boudjema, Abdelkader Bouadi Copyright (c) 2024 Tue, 14 May 2024 00:00:00 +0000 Effect of steel fibers and the fiber-concrete adhesion stress on the nonlinear shear behavior of beams <p class="referencias">In this article, a theoretical model in nonlinear elasticity is presented to analyze the influence of the percentage of steel fibers and the effect of the fiber-concrete bond stress on the shear force at the rupture of beams subjected to the combined effect of bending moment, normal force, and shear force. For a given beam section, it is defined by a succession of layers of concrete and longitudinal steel elements. Each layer is defined by its height hi, width bi, and position relative to one end of the section YGi. Each longitudinal steel element is also defined by its cross-sectional area and position relative to one end of the section. The steel fibers are defined by volume percentages of 0.5%, 1%, 1.5%, and 2%, taking into account the mechanical nonlinearity of the materials. This model is based on the multilayer analysis of sections and an iterative solution procedure for each layer and each section, considering a given longitudinal deformation state and shear stress. The global equilibrium of the sections is analyzed under the assumption of flat longitudinal deformations but with, in principle, an interdependence of longitudinal normal stresses and shear stresses. In this study, using the principle of virtual work, equilibrium equations for deformations and stresses, as well as partial compatibility equations between concrete deformations and mean deformations, are derived. Comparative examples between ordinary reinforced concrete beams with variable shapes and reinforcement details, and those reinforced with steel fibers, are presented to demonstrate the accuracy of the proposed model for simulating the nonlinear shear response of beams.</p> Djaloul Zarga, Abderahman Younsi Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 14 May 2024 00:00:00 +0000 A maintainable and iterative development approach of critical systems with FoCaLiZe <p class="referencias">The life-cycle development of critical systems follows mainly a V-cycle process overlapped with proofs and/or verification techniques. At the first development stage, a critical system must be, precisely, and as completely as possible described. Thus, it is recommended to use a graphical modeling language standard such as the Unified Modeling Language (UML) and the Object Constraint Language (OCL), to&nbsp;which both customers and developers could contribute. Then, the graphical design with its formal specification (requirements) is mapped into a complete formal development environment, using an MDE (Model-driven engineering) approach. The formal environment has to assess the development until the generation of a secure code. In this context, we propose a life-cycle development approach that combines UML/OCL and the FoCaLiZe formal environment for the secure development of critical systems. The proposed approach ensures essential development constraints such as strict boundaries and traceability between development phases. It also ensures a secure maintenance phase using partial transformation techniques from UML/OCL to FoCaLiZe. The latter enhances the transformation from UML/OCL into FoCaLiZe to support incremental development and assist developers in correcting modeling errors. The proposed approach is mostly dedicated to secure and maintainable lifecycle development processes of critical systems. The formal environment assesses the development process until the generation of a secure code. To illustrate the proposed approach, we present the stages of development of a constrained system controlling military objects. The development of this system uses the iterative, incremental, and maintainability stages as described by the development approach, until the generation of secure code.</p> Fatima Haloua, Messaoud Abbas, Ammar Boucherit, Hessa Alfraihi Copyright (c) 2024 Wed, 15 May 2024 00:00:00 +0000 Optimization of the concentration of ozone generated by DBD using PSO algorithm for water treatment process <p>The water treatment process with ozone is influenced by various operating parameters and environmental factors that can impact its efficiency. In this study, experiments were conducted using a Venturi pumping frame to investigate the effects of three controllable variables: oxygen flow height, applied voltage level, and water flow rate. The tests aimed to develop a mathematical model that accurately represents the relationship between these input variables and the resulting ozone concentration in the treated water. The experimental data was analyzed using the MODDE 5.0 software, a specialized application for statistical modeling and design of experiments. By fitting the data to appropriate model equations, a mathematical model was obtained that quantifies the influence of each variable and their interactions on the ozone concentration response. To optimize the process performance, a particle swarm optimization (PSO) algorithm was employed to extract the best-fit parameters for the mathematical model. PSO is a computational technique inspired by the social behavior of bird flocks or fish schools, utilizing a population of candidate solutions that evolve iteratively to converge on the global optimum solution. In this case, PSO searched for the model parameter values that minimized the error between predicted and experimentally measured ozone concentrations, rapidly converging to an accurate solution. The optimized mathematical model enables predicting the ozone concentration under any combination of oxygen flow height, voltage, and water flow rate within the experimental range. This predictive capability facilitates identifying the optimum operating conditions to maximize ozone concentration, thereby enhancing the efficiency of the water treatment process. The model serves as a valuable tool for process control, monitoring, and optimization, ensuring consistent treatment quality while minimizing resource consumption and operational costs.</p> Ghaitaoui Essama Ahmed, Nassour Kamel, Said Nemmich, Touhami Ghaitaoui, Oulad Naoui Brahim El Khalil, Yassine Bouroumeid, Amar Tilmatine, Youcef Halali Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 16 May 2024 00:00:00 +0000 On Bayesian premium credibility: maximum entropy prior for unknown claims process and numerical example <p>In the complex field of insurance, determining the credibility of the most efficient premium is a major challenge, especially when the distribution of claims remains unknown. This study uses a Bayesian methodology to address this issue. In this framework, the initial assumptions concerning the unidentified parameters of the claims process are expressed by means of a distribution function. The objective is to establish premium credibility by maximizing the insurance company's expected utility while respecting specific constraints. By applying the maximum entropy method, we can derive the posterior distribution of the loss process from the observed data available. This approach is advantageous because it offers modeling flexibility and enables estimates to be progressively updated as new data becomes available. It is also particularly useful in situations where data is limited or incomplete, as is often the case in the insurance sector. The study highlights the characteristics and advantages of this Bayesian method. It highlights how the approach handles uncertainty and integrates prior knowledge into the estimation process. In addition, several numerical illustrations are included to demonstrate the practical application of the method and its impact on determining premium credibility. In summary, this research offers an innovative perspective on risk management in the insurance sector. It proposes a method that not only adheres to the playful approach to risk management, but also to the premium credibility approach.</p> Naim Boudjelida, Mohamed Riad Remita, Halim Zeghdoudi Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 16 May 2024 00:00:00 +0000 Novel composite model: application in epidemic and actuarial science <p>Actuarial sciences frequently use Nakagami and Pareto distributions to model their payment data. The Nakagami distribution is frequently employed for modeling the lifespans of things that are affected by their age, and it possesses a multitude of practical applications. Alternatively, academics sometimes utilize the Pareto distribution to model payments data, especially for instances of substantial loss data or reinsurance payments. The present study presents and investigates a new composite model known as the composite Nakagami-Pareto distribution (CNPD), which integrates components from both the Nakagami and Pareto distributions. When examining composite distributions, the first distribution is usually characterized by a thin tail, whereas the next distribution has a thick tail. In the Nakagami-Pareto model, the Nakagami density is chosen as due to its characteristic of being a light-tailed distribution. Similarly, the Pareto distribution is selected as because it exhibits a heavy-tailed distribution. An investigation has been conducted to assess the practical usefulness of the composite Nakagami-Pareto model when applied to real-world data sets. This analysis has emphasized the significant components of the model. Statistical qualities such as cumulative distribution function, quantile function, mode, first moment, ad-hoc procedure and maximum likelihood estimation have been established. Furthermore, a method for estimating has been described utilizing a data sample derived from the Composite Nakagami-Pareto model. The composite exponential-Pareto and the composite lognormal-Pareto distributions' resultant densities have similar shapes, but their tails are more noticeable. Therefore, we anticipate that our model will be more suitable than the composite exponential-Pareto distribution, composite lognormal-Pareto distribution, and other traditional one (or two)-parameter distributions. The significance and practicality of this novel approach were demonstrated by analyzing simulated cases, data sets are available for the recovery periods (measured in weeks) of 75 persons from Angola who were infected with the Marburg virus, as well as for 2156 fire insurance losses in Denmark.</p> Moulouk Halima Benchettah, Halim Zeghdoudi, Raman Vinoth Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 16 May 2024 00:00:00 +0000 Identificação de fatores de riscos ergonômicos na atividade de expurgo de uma central de esterilização hospitalar <p class="referencias"><span style="letter-spacing: .1pt;">Objetivos: O presente estudo teve por objetivo identificar os fatores de riscos ergonômicos presentes na atividade de trabalho no setor de expurgo da Central de Material e Esterilização (CME) de um Hospital Universitário (HU), bem como, analisar o perfil sociodemográfico e profissional dos Técnicos de Enfermagem que atuam no setor. Metodologia: Participaram do estudo 22 trabalhadores enquadrados no cargo de Técnico de Enfermagem, conforme a Classificação Brasileira de Ocupação (CBO) 3222-05. O instrumento de coleta de dados utilizado foi um roteiro elaborado pelos autores e o Questionário Nórdico para sintomas musculoesqueléticos, ambos aplicados in loco em outubro de 2021. O presente estudo foi aprovado pelo Comitê de Ética em Pesquisa da UFSC e protocolado com o nº CAAE 51539021.9.0000.0121, sendo aprovado sob nº 5.003.058 em 28/09/2021 Resultados: As principais atividades identificadas que apresentam risco ergonômico foram a permanência na posição em pé, a inserção de materiais na lavadora termodesinfectora, a repetitividade de lavação e a esfregação dos materiais foram as principais. Ainda, 77,8% dos entrevistados declararam sentir ou terem sentido dor nos punhos e mãos, 66,7% no quadril e coxas e 55,0 % no pescoço e ombros nos últimos 12 meses. Considerações Finais: Conclui-se que as atividades desempenhadas no setor da CME possuem relação com os distúrbios Osteomusculares Relacionadas ao Trabalho identificados, cujas regiões corporais afetadas tem histórico de nexo causal com as atividades desempenhadas pelos profissionais vinculados ao setor. Portanto, para a melhora das condições de saúde desses profissionais, seria imprescindível repensar as condições ergonômicas no local, bem como repensar o fluxo das atividades, fatores que contribuem para a melhoria da qualidade de vida no trabalho. </span></p> Davi Avelino da Silva, Jerko Ledic Neto, Michela Lizzi Lagranha, Tiago Aurélio Alves, Antônio Renato Pereira Moro, Lizandra Garcia Lupi Vergara Copyright (c) 2024 Fri, 17 May 2024 00:00:00 +0000 Solid foam composite derived from cement and jujube core activated carbon: a sustainable adsorbent for textile wastewater treatment <p class="referencias">The textile industry is responsible for a significant amount of environmental damage caused by the use of dyes, which puts the health of humans and the ecosystems in the surrounding area in dire danger. The conventional approaches to wastewater treatment can be rather expensive and demand a significant amount of energy. Regrettably, these techniques are not very efficient when it comes to dealing with the substantial quantities of coloured wastewater that are generated by the textile sector. The utilisation of cement-activated carbon solid foam composite technology is a viable option that offers significant advantages in terms of both efficiency and environmental impact. These solid foam adsorbents are produced by the utilisation of a manufacturing process that is environmentally friendly and ingredients that are sourced locally, such as jujube cores. Even at low initial dye concentrations, they had clearance rates of over 98%, which is an impressively high percentage from their dye retention capabilities. In order to demonstrate the composite's potential for use in wastewater treatment applications, characterization techniques such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and EDX are utilised. After conducting in-depth research, it has been established that the mass of the adsorbent and the length of time that it is in contact with the substance have a significant impact on the removal efficiency. The most favourable conditions have been seen to occur within a time range of ninety minutes, according to those observations. Methylene blue can be effectively removed with the help of the solid foam Composite, which is a sorbent that is not only readily available but also practical, cost-effective, and readily available. According to the findings of equilibrium research, the Temkin isotherm model is the one that is most suitable for understanding the behaviour of adsorption. As an additional point of interest, desorption experiments have shown that there are strong bindings between the dye and the composite, which indicates that there is minimal reversibility.</p> Mohammed Ettahar Boussalah, Malika Medjahdi, Sofiane Guella, Nadia Ramdani, Dominique Baillis Copyright (c) 2024 Fri, 17 May 2024 00:00:00 +0000 Bearing capacity evaluation of embedded circular footing considering presence of an overload adjacent <p>The bearing capacity of axially loaded embedded foundations has been widely studied using analytical and numerical methods. However, there are many discrepancies in the literature results regarding the bearing capacity factors and depth factors of circular embedded footings proposed by different authors. Terzaghi's hypothesis has been used to assess the bearing capacity of shallow foundations and several analytical solutions have been proposed for computing bearing capacity factors, even though a superposition of individual contributions may lead to some error in the computed bearing capacity.&nbsp; This assumption has sometimes been criticized as being more conservative. This article aims to study two problems; The first part is focuses on the numerical evaluation of the superposition hypothesis in the calculation of the bearing capacity for rough circular foundations embedded in sand. In this section, the bearing capacity factors contributing to the conventional solution have been evaluated and superposition errors are indicated and compared with those found&nbsp; by different authors. The latter part of the work is devoted to studying the depth effect on the estimation of the bearing capacity of a rough circular footing embedded in the sand considering presence of an overload adjacent. For both analyses, the finite-difference code Flac2d (FLAC 2007) was used to reach the bearing capacity for embedded circular footings, the ground friction angles are between 25° and 40° and a depth ratio Df/D varies from 0.1 to 2. The calculation results are presented in tables and graphs and compared to previously published results available in the literature.</p> Mounia Belkacem , Sadok Benmebarek , Insaf Saifi Copyright (c) 2024 Fri, 17 May 2024 00:00:00 +0000 Effects of geometry and flow rate on the mixing process in passive Y-micromixer <p>In this work, we look at the mixing capabilities of a static Y-micromixer, which achieves very good mixing quality when compared to other recently proposed micromixers in terms of mixing quality. We propose to change both the quantity and arrangement of element pairs. The 3D momentum equations, continuity equation, and species transport equations have all been solved numerically at moderate Reynolds numbers using the CFD Fluent tool. The lengthening of the Y-shape is determined by the quantity of pairings. A comprehensive analysis was conducted by varying the number and position of element pairs across a broad spectrum of Reynolds numbers, ranging from 1 to 400. The numerical simulations examined the acquired outcomes by displaying the contours of mass fraction, vorticity, mixing performance and pressure losses in various planes. The chosen geometry, consisting of 4 pairs of components, has exceptional mixing capabilities. The mixing index surpasses 47% at Re = 1 and achieves a maximum of 99% at Re = 400. Furthermore, it exhibits a reduced pressure drop in comparison to other recently examined geometries. Hence, the chosen micromixer demonstrates excellent mixing capabilities at moderate Reynolds numbers, rendering it suited for improving fluid mixing in diverse microfluidics systems.</p> Abdelkader Mahammedi , Amari Abderrahmane , Driss Meddah Medjahed, Nassira Medjadji Copyright (c) 2024 Fri, 17 May 2024 00:00:00 +0000 Removal of the bemacid blue E-TL using granular activated carbon from abundant biomass: adsorption isotherm, thermodynamic and kinetic studies <p>In this work, we were interested in the adsorption of an acid dye, Bemacid Blue E-TL by granular activated carbon based on olive stones. To shed light on the adsorption process, batch experiments were performed to study the effect of operating parameters on the adsorption process such as equilibrium time, GAC dose, pH, initial dye concentration, and temperature. The experimental results showed that the adsorption of the dye Bemacid Blue E-TL by GAC based on olive stones depends on the equilibrium time at 8 hours, the pH is 2 of the solution and the dose is 5 g.L<sup>-1</sup>. To explain the adsorption equilibrium, the experimental values were examined by Langmuir, Freundlich, and Temkin models. The equilibrium is perfectly described by the Langmuir model whose correlation coefficient is higher than 0.99. The maximum retained quantity of the Bemacid Blue E-TL is 55.6 mg.g<sup>-1</sup>. Different kinetic models such as pseudo-first order, pseudo-second order, and the intraparticle diffusion equation were used to evaluate the adsorption kinetics. The results of the kinetic modeling showed that the pseudo-second order fitted the data well, with a high coefficient of determination (R<sup>2</sup> &gt; 0.99) and intra-particle diffusion is not the only rate-limiting step. The thermodynamic parameter values enthalpy (ΔH°), entropy (ΔS°), and energy change (ΔG°) show that the adsorption processes are endothermic and spontaneous. The various results obtained are promising and encouraging to consider a more comprehensive study with the objective of showing that the adsorbent chosen for this study is effective and could be used as a low-cost adsorbent for acid dye removal.</p> Mokhtar Benzekri Benallou, Zohra Mekibes, Nadia Douara, Mohammed Amin Chemrak, Mourad Termoul, Salima Attouti, Noureddine Benderdouche, Benaouda Bestani Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 20 May 2024 00:00:00 +0000 Non-destructive rapid defect testing around curved head rivets without displacement of eddy current sensors <p>In the field of aeronautics, it is essential to ensure the structural integrity of aircraft components. Non-destructive testing (NDT) plays a crucial role in ensuring the safety and reliability of structures used in aeronautics as it enables the detection of defects and imperfections without damaging the inspected parts. Domed head rivets are commonly used in aeronautics to assemble multilayer structures due to their strength and ability to maintain the structural integrity of aircraft. However, inspecting these assembly areas can be challenging and presents unique challenges in terms of non-destructive testing due to the curved surface of the rivet, resulting in lift-off variation during surface scanning and a modification of the trajectory of eddy currents near the rivet. This can lead to changes in the response of eddy currents, complicating the accurate interpretation of test results. In recent years, researchers have focused on developing advanced eddy current testing methods to detect defects in complex structures, such as those found in aeronautics. In this work, we propose a promising solution to address both the shape of the rivet and the probe displacement issue during testing. We have developed a model based on the finite element method (FEM) using COMSOL Multiphysics for non-destructive testing through 3D imaging using a matrix of multiplexed multi-element eddy current sensors distributed over multiple layers around the rivet without the need for the displacement of this matrix and capable of adapting to the variation in the diameter of the domed head rivet. The non-displacement of the sensors eliminates parasitic signals that can lead to errors in the interpretation of obtained signals, and the multiplexed powering of the sensors eliminates the mutual inductance effect between adjacent coils.</p> Merwane Khebal, Abdelhak Abdou, Tarik Bouchala, Abderrahmane Aboura, Abdelhadi Bachir, Guettafi Amor Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 21 May 2024 00:00:00 +0000 The Lindley generalized Pareto distribution: properties, estimation and application to COVID-19 data <p>In this paper, we introduced a new distribution called Lindley Generalized Pareto distribution (LGP), a novel lifetime model derived by combining the Lindley and the generalized Pareto distributions. The corresponding density and distribution functions are derived and shown. Some of the derived statistical properties of the distribution include survival and hazard functions, moments, cumulants, the quantile function, mean deviations, and Entropy are studied. The parameters of the newly distribution are estimated by using Maximum Likelihood method. The adaptability and validity of the proposed LGP distribution are compared via simulation study with alternative known models. In addition, three real data of COVID-19 mortality rates applications are presented to demonstrate that the LGP distribution fits better than known extensions of the Lindley distribution, including the Lindley, XLindley, Power Lindley, gamma Lindley, PXLindley, A Three Parameters Generalized Lindley, Weibul Lindley, Generalized Lindley and Extended Lindley, through analyses of three real datasets.</p> Kahloul Bariza, Yahia Djabrane Copyright (c) 2024 Tue, 21 May 2024 00:00:00 +0000 Developing a seismic bridge reliability model to enhance its resilience: a study on reinforced concrete bridges in Algeria <p>Bridges are critical points in transportation networks because they are exposed to various natural and human-caused hazards, leading to partial or complete service interruption. Bridges must maintain their societal functions, especially after events such as earthquakes, because they play a vital role in emergency response, relief operations and damage mitigation. This paper proposes an improved model for evaluating the reliability of reinforced concrete bridges before seismic events, to improve their resilience to earthquakes and enable effective preparedness for disasters. In the first phase of this study, a group of important factors that affect the reliability of the bridge were identified, based on the opinions of experts and a comprehensive reading of the current literature in this field, These factors include the current physical condition of the bridge, the seismic hazard, the seismic design, the importance of the bridge in terms of traffic, and the geometry of the bridges. In the second stage, the Analytical Hierarchy Process (AHP) was used to determine the relative impact of each factor compared to other factors.The third stage is to calculate the bridge's seismic reliability index (RSI) by combining the weights of these factors with the score for each case.Three classifications of seismic reliability were proposed for low, medium and high. The model has been applied to many reinforced concrete bridges in earthquake-prone areas in Algeria. The model provides valuable insights for evaluating bridge reliability and can help decision makers and officials make proactive decisions that will improve seismic resilience. Finally, the results obtained are summarized in this paper.</p> Mohammed Abdellaoui, Mohamed Badaoui, Mahmoud Bensaibi, Koriga Said Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 21 May 2024 00:00:00 +0000 Enhancing fuel cell efficiency through advanced digital twin modeling <p>In this study, we embark on a comprehensive exploration aimed at advancing Fuel Cell Modeling through the sophisticated computational capabilities offered by Matlab Simscape. Our primary objective is to engineer an advanced digital twin that not only replicates but faithfully captures the intricate characteristics inherent in real-world Fuel Cell models. This digital counterpart assumes a pivotal role in our research, serving as a dynamic tool for continuous monitoring of the operational dynamics exhibited by actual Fuel Cells. It stands as a dependable reference point, enabling us to delve deeper into the complexities of these systems. However, the significance of our digital twin transcends mere emulation. It emerges as a stable benchmark against which deviations in real Fuel Cell data can be discerned and analyzed, thereby facilitating meticulous error analysis. Through meticulous alignment with its physical counterpart, our approach offers a precise instrument for anomaly detection, providing invaluable insights into potential errors within the authentic Fuel Cell system. This innovative methodology not only enhances the efficiency of error detection but also revolutionizes the comprehensive evaluation of reliability and performance within the fuel cell domain under scrutiny. By integrating state-of-the-art computational capabilities with the intricacies of real-world systems, our research signifies a paradigm shift in the study and optimization of fuel cell technologies. The intricate interplay between simulation and reality paves the way for a deeper understanding of fuel cell behavior, enabling us to uncover nuances that were previously inaccessible. This holistic approach not only improves our ability to detect and rectify errors but also enhances our capacity to optimize fuel cell performance in diverse applications. Ultimately, our research endeavors to bridge the gap between theoretical modeling and practical implementation, offering a robust framework for advancing the efficiency, reliability, and performance of fuel cell systems in real-world scenarios.</p> Yacine Benchenina, Abderrahim Zemmit, Mohammed Moustafa Bouzaki Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 21 May 2024 00:00:00 +0000 Development of an intelligent Arduino-based power factor corrector for a domestic installation powered by solar panels <p>Power factor correction using capacitor banks reduces reactive power consumption, leading to minimization of losses while increasing the efficiency of the power system. The issues of energy saving and reactive power management have led to the development of single-phase capacitor banks for domestic applications. The development of this project consists of improving the operation of single-phase capacitor banks to improve the operation of a domestic solar installation by developing a control system based on the Arduino. The control unit will be able to control the operating stages of the capacitor bank based on the variable charging current. To properly calculate the power factor in real time, we used two sensors, however, the current sensor is used to measure the load current for sampling purposes and the voltage sensor to measure the voltage. Intelligent control using this microcontroller control unit, calculates the current/voltage phase shift and ensures uniform utilization of capacitor stages, minimizes the number of switching operations and optimizes power factor correction. In order to validate the proper functioning of our project, we installed the latter in a PV installation of 2kW in total, the latter is installed within the energy engineering and electrical engineering laboratory, thus this installation is equipped with different types of load such as as the purely resistive, purely inductive load and the asynchronous motor which represents the inductive load. The values obtained by the device and displayed on the LCD are confirmed using the oscilloscope by plotting the currents and voltages. The results obtained show the success of this project and the efficiency of the device has improved the power factor.</p> Bey Mohamed, Drias Souhil Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 22 May 2024 00:00:00 +0000 FEM analysis of thermomechanical effects on stress intensity factors <pre style="text-align: justify;"><span lang="PT" style="font-size: 12.0pt; font-family: 'Arial',sans-serif;">The response of a material to thermo-mechanical loading depends on its thermal and mechanical properties. Some materials may exhibit significant thermal expansion, meaning they expand significantly when heated, while others may be stiffer and show little thermal expansion. To evaluate the behavior of a material or structure subjected to thermo-mechanical loading, advanced analysis and modeling techniques are used, such as finite element modeling. These methods make it possible to predict deformations, stresses and possible failure problems that may occur under the effect of thermo-mechanical loading. In the present paper, assuming that the thermal regime was steady, the effects of thermo-mechanical loads on the stress intensity factor in a 2D cracked plate of functional gradient material (FGM) are examined. The analyzes the effects of thermo-mechanical loads on the stress intensity factor in a 2D cracked plate of functionally gradient material is a complex problem and generally requires advanced modeling and simulation approaches, such as the finite element method. <span class="y2iqfc">The plate has a crack on the edge and is made of FGM (titanium-zirconia).</span> Analyses are performed for different imposed temperature values, using the Newman’s conditions. The problem is solved using a newly created USDFLD subroutine in the ABAQUS program. In this routine, functionally graded material property variations follow an exponential law function in the plate with cracks. <span class="y2iqfc">S</span>tress intensity factor<span class="y2iqfc">s are calculated using the J-integral, taking into consideration the variation in properties at the crack tip.</span> Effects of temperature and relative crack length on stress intensity factors were evaluated. <span class="y2iqfc">The </span>stress intensity factor<span class="y2iqfc"> values obtained by the finite element method (FEM) modeling shows that there is a good correlation with the results obtained in other studies.</span></span></pre> Brahimi Abdelghani, Tayeb Kebir, Mohamed Benguediab, Andrea Carpinteri Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 22 May 2024 00:00:00 +0000 S-asymptotically ω periodic solutions of heat equation <p>We mean by an S-asymptotically ω-periodic function any continuous and bounded function from the real axis to a Banach space that converges to a periodic function as t tends to infinity. We study in this paper the existence, uniqueness and differentiable dependence on the S-asymptotically ω-periodic mild solution of a heat equation on the space of continuous functions from a non-empty n-dimensional bounded domain with a Lipschitz boundary to the real axis. The dependence of the solution concerns the initial conditions, more precisely when the initial conditions is a S-asymptotically ω-periodic function we study the differentiable dependence of the S-asymptotically ω-periodic solution of heat equation. To show our main result in this work we introduce the properties of the superposition operator, or also called Nemytskii operator, in the space of S-asymptotically ω-periodic functions. The notion of derivation for the last operator will also be highlighted. We also use in this paper semi-groups which have become important tools for differential equations. In this study, our focus shifted from seeking an s-asymptotically w-periodic solution for our heat equation, which is a problem in dynamic systems, to one in functional analysis. More precisely, our strategy consists of applying the implicit function theorem on a certain operator that we constructed on our workspaces in order to achieve the objective described in our main theorem. In fact our theorem gives conditions to ensure that around a mild S-asymptotically ω-periodic solution of our heat equation with an initial value, there exists a regular (in the usual sens) mild S-asymptotically ω-periodic solution which depends on a neighboring initial condition.</p> Abdelkader Bouadi, Souhila Boudjema Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Fri, 24 May 2024 00:00:00 +0000 Assessment of slope stability with study parametric of faults (shear joints) using the lower and upper limit analysis method <p>Slope instability is widespread throughout the world, has become well known to geotechnical engineers, and poses a major challenge. The causes of slope slippage vary, which is why it is considered important and dangerous. Until now, researchers are trying to understand this phenomenon and the extent to which it is affected by surrounding elements, such as the slope ratio, slope height, water level, soil properties, and other physical and chemical properties. In this research, we will discuss one of the characteristics, which is the presence of cracks on slopes. The presence of combined shear on slopes poses a challenge to geotechnical engineers to determine field mechanical parameters, analyze, and study these slopes. In this research, we studied the effect of faulting on slopes. We changed the crack in the slope in five cases, and in each case we changed the length of the crack (21.5 m, 16.2 m, 11.2 m, 7.5 m, 3.5 m) and its location (five places) in order to understand a fracture. Slope behavior as a result of the effect of crack length and location on the safety factor, failure of the slope surface, and deformations of this slope using the top and bottom analysis method. This study provides valuable insights into the effects of fault zones on slope stability using OptumG2 software. It is helpful for us to use these results to better understand slope sliding, and from this, we can reduce the risk of sliding in areas where cracked soil is present.</p> Hosni Abderrahmane Taleb, Ismahene Guemidi, Zaouai Said Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 27 May 2024 00:00:00 +0000 Investigation of pad radius effects on multiaxial fretting fatigue behavior of al2024 alloy <p class="referencias" style="text-align: justify;">Fretting fatigue, a critical phenomenon prevalent in engineering applications, occurs at the interface of contacting surfaces under cyclic loading, presenting significant challenges. The advent of Finite Element Analysis (FEA) has transformed the investigation of fretting fatigue by offering detailed insights into stress distributions and fatigue damage mechanisms. This study delves into the impact of pad radius on the fretting fatigue behavior of Al2024 alloy using FEA, with a focus on hot spot analysis and the Smith-Watson-Topper (SWT) criterion. The analysis aims to validate numerical results against analytical findings and explore the role of pad radius in determining contact behavior, fatigue life, and hot spot locations. By incorporating "fe-safe" software, computations are streamlined, facilitating efficient comparison of different fatigue initiation criteria. The results demonstrate that variations in pad radius significantly influence fretting fatigue behavior. Larger pad radii tend to distribute stresses more uniformly across the contact interface, resulting in reduced fatigue damage and longer fatigue life compared to smaller pad radii. Hot spot analysis reveals that smaller pad radii concentrate stresses at specific regions, accelerating fatigue damage initiation. The findings contribute to a deeper understanding of fretting fatigue mechanisms, shedding light on the importance of pad radius in designing more durable engineering components. Through professional scientific methodology, this study provides valuable insights into optimizing pad design to mitigate fretting fatigue and enhance the reliability of mechanical systems.</p> Abdelghani Baltach, Ali Taghezout, Mohamed Ikhlef Chaouch, Ali Benhamena, Abdelkader Djebli Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 27 May 2024 00:00:00 +0000 Diagnosis of a DC-DC converter boost using the Artificial Neural Networks ANNs <p>As we know in most the components of electrical equipment age during their operational life, which can be more or less long depending on the nature and degree of stress to which they are subjected, resulting in a degradation of performance to improve the reliability of the system. Industrial applications the DC machines are powered by a chopper voltage source. These machines are sensitive to different types of defects occurring to switches, capacitors and coils the need to conduct studies for the detection, localization and maintenance of defects become crucial. To avoid serious faults in DC-DC converters, several concepts have been applied to the diagnosis of these. The ANN method is used to diagnose DC-DC converters.</p> Naas Djeddaoui, Naas Charrak, Zemmit Abderrahim, Lakhdar Bessissa, Imad Eddine Tibermacine, Karboua Mohamed Adel Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Mon, 27 May 2024 00:00:00 +0000 sEMG biceps and triceps effort signals classification using 1D-CNN convolution <p>In this paper, we present a system for acquiring and classifying surface physiological muscles signals (sEMG) for the biceps and triceps muscles during movement or work, as normal or aggressive effort in order to control and command the aid prostheses to intervene only during aggressive efforts. Thus, the main objective of our work is to developing and improving the performance of the hand prostheses for daily life tasks for elderly persons or for persons who have hand muscle failure. Our contribution consists of detecting and classifying physiological signals of biceps and triceps muscles hand as normal and aggressive efforts, for that we proposed a technique based on a 1D Convolutional Neural Network (CNN-1D) using the Wavelet Scattering Transform as the sEMG feature extraction technique. Our methodology is carried out in two steps: the first step is crucial to build a database for deep learning network for sEMG signals classification based on fifty-five volunteers spanning various ages and genders. The second step achieves the sEMG signals effort classification as normal or aggressive efforts based on the classification network produced based on sEMG signal sequences treated by the WST. The obtained results for the training and validation sets indicate perfect performance of the proposed technique, with an accuracy, precision, sensitivity, and specificity of 100% for the training process, and 99.3%, 98.6%, 100% and 98.7% for the accuracy, precision, sensibility and specificity respectively. It is important to note that while perfect metrics on the training and the test set might suggest excellent model learning.</p> Sofiane Tchoketch Kebir, Fouaz Berrhail Copyright (c) 2024 Mon, 27 May 2024 00:00:00 +0000 Application of the FMECA method on the electro-hydraulic system for drilling machine type NKH45 <p>This article focuses on the implementation of a preventive maintenance strategy, responding to a major challenge: the search for optimization in minimizing downtime of the radial drilling machine (NKH45). Crucially positioned at the heart of the mechanical manufacturing process, this machine holds significant influence on overall production performance and availability. In consideration of the strategic importance of this equipment within the framework of the mechanical manufacturing activity, an advanced methodology, in particular FMECA (Failure Mode Effects and Criticality Analysis), is implemented. FMECA represents one of the most recommended approaches in this context, based on reliability, allowing the meticulous identification of the main causes of functional failures of equipment. FMECA is a risk prevention method. It is used to improve the reliability of a product, a process or even a means of production. It makes it possible to assess the criticality of potential failures in a system. According to the recommendations of the maintenance department of the company specializing in the construction of agricultural equipment, this study will focus on a subsystem of the electro-hydraulic part of the NKH45 radial drilling machine, we use the FMEA Analysis method (Failure Mode Effects and Criticality Analysis). Thanks to this approach, it is possible to identify the main reasons for equipment breakdowns that affect production and to classify these breakdowns in order to develop an optimal maintenance strategy aimed at: reducing the number of breakdowns, preventing breakdowns, improving the preventive maintenance, reduce downtime, improve corrective maintenance, therefore the ultimate objective of this approach is to design an optimal maintenance action plan in order to significantly minimize downtime, which slows down production flow.</p> Abdelhak Elhannani, Abbes Elmeiche, Mohamed Bouamama, Toufik Bousnane Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 28 May 2024 00:00:00 +0000 Fine particle capture performance assessment in an electrostatic-fabric integrated precipitator <p>Electrostatic precipitators, which are more commonly referred to as precipitators, play a crucial role in the process of reducing the quantity of airborne contaminants that are present in both atmospheric and flue gas settings. This is because precipitators are able to lower the concentration of contaminants in the air. The fine particles, ash, and oil that make up these pollutants are included. With a special emphasis on a Cottrell-type electro-filter that makes use of the wire-cylinder arrangement, the goals of this study are to evaluate the practicability of various filtration systems for the purpose of air decontamination. Specifically, the study will focus on the Cottrell-type electro-filter. By conducting a thorough examination of the peculiarities of the electrical and physical parameters that regulate the mechanisms of particle aggregation, our major purpose is to achieve a comprehensive understanding of these parameters. Through the use of experimental design strategies, we will make an effort to construct and perfect the filtration process in the subsequent stage. In addition to that, the purpose of this inquiry is to explore the impact that high voltage levels and the diameter of the conductor wire that is incorporated into the prototype have. Especially notable is the fact that our prototype exhibits an incredible filtration efficiency, with rates reaching up to 98%. This performance is really remarkable. Its exceptional performance reveals that it has the potential to be suitable for a wide variety of contexts, including residential, commercial, healthcare, industrial, and workshop applications. This suggests that it has the potential to be suitable for a wide range of applications.</p> Dahbi Hassane, Iliace Arbaoui, Ali Abderrazak Tadjeddine, Touhami Ghaitaoui Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 28 May 2024 00:00:00 +0000 Sensorless fuzzy-sliding mode control of five phases permanent magnet synchronous motor using MRAS: in three different operating modes <p>This paper presents a comprehensive study on sensorless control techniques for five-phase permanent magn<em>et </em>synchronous motors (5P-PMSMs). To optimize the speed control performance of (5P-PMSM), which has more advantages than its counterpart three-phase PMSM system, we utilized a combination of fuzzy logic and sliding mode control techniques to optimize the proposed sliding mode control. Additionally, the Model Reference Adaptive System (MRAS) is employed to estimate the speed and rotor position of the 5P-PMSM to enhance the robustness and adaptability of the control system. The modelling of the machine, detailed with a robust nonlinear strategy based on the sliding control, is introduced to track the system until the desired sliding surface is achieved first. To guarantee that the tracking errors converge, the sliding mode control has a chatter due to the discontinuous term. To mitigate the drawback, the proposed control is designed by combining SMC with fuzzy logic, enhancing the performance in a steady state. Examining the control performance of the integrated control fuzzy-SMC with MRAS in different operating modes, including three tests in reversal speed operation, open phase fault mode, and the low-speed operating mode under load torque. The main aim is to assess and analyze the robustness and performance of the proposed control strategy. The stability of the overall control system is examined using the Lyapunov theorem and Popov’s theory analysis of MRAS observer stability. The simulation results of the suggested control displayed by MATLAB-Simulink illustrate the effectiveness and adaptability of the sensorless control scheme across different operating conditions, offering promising prospects for practical implementation in industrial applications.</p> Haithem Boughezala Hamad, Kouider Laroussi, Saad Khadar, Yousfi Mohammed Amin, Allag Omar Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 29 May 2024 00:00:00 +0000 Optimization of a hybrid system (PV-fuel cell) of energy production for an isolated site <p>In recent years, there has been a significant shift in the design and implementation of autonomous micro-grid systems, moving away from the traditional reliance on fossil fuels. Instead, these systems are now integrating existing renewable energy sources available in specific geographic locations to promote sustainability and environmental responsibility in the energy sector. One particularly promising approach for energy storage and transmission is through the utilization of hydrogen and solar energy, especially in remote regions where hybrid techniques can effectively meet the required energy demands. Our research focuses on electrifying an agricultural site located in the SBAA region, specifically in the city of ADRAR, southwest Algeria. We propose the implementation of an independent small electric network that combines various renewable energy sources, including photovoltaic (PV) systems and fuel cells. To ensure cost-effectiveness and optimize the system's performance, we aim to carefully control and size the system's components through a meticulous selection process. The primary objective of this study is to evaluate the technical and economic feasibility of implementing renewable energy systems in the targeted region. Our goals are to reduce the total net cost, minimize energy expenses and unfulfilled load, while simultaneously mitigating CO2 emissions. To achieve these objectives, we employ the HOMER Pro simulation program, which enables us to conduct a comprehensive analysis of the proposed system's performance and economic viability. The proposed system incorporates a hybrid configuration of PV panels and fuel cells, leveraging the complementary nature of these two renewable energy sources. PV panels harness the abundant solar energy during daytime hours, while fuel cells provide a reliable and consistent energy source during periods of low solar irradiance or at night. By integrating these two technologies, we aim to establish a self-sufficient and sustainable energy system capable of meeting the energy demands of the remote agricultural site. Overall, the proposed renewable energy system demonstrates positive results in electrifying remote areas while maintaining a conservative cost of electrical energy. By implementing this system, we not only contribute to the establishment of sustainable regions but also promote environmental stewardship by reducing carbon emissions and dependence on fossil fuels.</p> Ghaitaoui Touhami, Sliman Laribi, Arbaoui Iliace, Ghaitaoui Essama Ahmed, Halali Youcef, Touhami Drissi, Ibrahim Ben Omar, Bouchra Benabdelkrim, Hassane Dahbi Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 29 May 2024 00:00:00 +0000 Acoustic analysis and control measures for noise in university: a case study of Adrar University, Algeria <p>The purpose of this research is to investigate the complex dynamics of noise pollution at the University of Adrar-Algeria, with a particular emphasis on the impact that the dry desert climate has on the acoustic environment of the campus. With the goal of cultivating an environment that is characterised by tranquilly, comfort, and optimal conditions for attention, learning, and practical engagement, the research attempts to achieve the goal of enhancing the existing discourse on noise management inside academic institutions. The inquiry makes use of a methodical approach in order to investigate the many climatological characteristics that are unique to the desert climate and that lead to increased noise levels within the university grounds. In addition, the research investigates the ways in which noise emissions from various sources alter inside the confines of Adrar University, taking into account the ways in which the harsh desert climate influences the parameters that control these emissions. The investigation of human behaviour patterns is relevant to this investigation. In particular, the investigation will focus on instances of protracted assemblage in air-conditioned places, which correlates with increased noise levels. In light of the fact that noise control is an essential component of the academic environment, the research being conducted at the University of Adrar includes the collection of questionnaires, the administration of on-site sound measurements, and the creation of an all-encompassing noise map. The findings shed light on the climatic factors that are primarily responsible for the excessive amount of noise that exceeds the standards that are suggested by the World Health Organisation (WHO).</p> Iliace Arbaoui, Touhami Ghaitaoui, Ali Abderrazak Tadjeddine, Hamza Bradaiha, Dahbi Hassane, Ahmed Hamou Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 29 May 2024 00:00:00 +0000 Robust line voltage sensor-less control of grid-connected MMC converter in PV Applications <p>This paper discusses the voltage sensor-less control of a single-phase grid-connected Modular Multilevel Converter (MMC) in photovoltaic (PV) applications. The design of the control system is crucial to efficiently injecting PV power into the main grid. Therefore, three control targets are designed. Maximum power point tracking (MPPT) through the Incremental Conductance (IC) algorithm, DC link voltage regulation, and finally output active and reactive power controlling throughout the regulation of grid current amplitude and phase shift. To achieve those targets, the value of grid voltage has to be known accurately. The main contribution of this study is the use of a Simplified Super Twisting Algorithm Sliding Mode Observer (SSTA-SMO) for grid voltage estimation. The effectiveness and satisfactory performance of the proposed system are validated through simulations via MATLAB. To verify the effectiveness of the proposed approach. A study was conducted to evaluate the efficacy of the SSTA-SMO proposal in comparison to a traditional sliding-mode observer. The objective was to showcase the superiority of the proposed approach. The results suggest that the suggested observer surpasses other methods in terms of several aspects, including minimal errors in grid voltage observation, high-quality estimation of grid voltage, and accurate tracking of the reference. Furthermore, it exhibits robustness when exposed to different levels of radiation.</p> Imane Alia, Imad Merzouk, Mehamed Mounir Rezaoui Copyright (c) 2024 Wed, 29 May 2024 00:00:00 +0000 Influence of choosing materials on 6/4 switched reluctance motor performance <p>The Switched Reluctance Motor<strong> (</strong>SRM<strong>)</strong> is used in many industrial applications that require high torque due to its ability to achieve high and efficient performance, simplicity, low material costs and ease of design. This motor functions on the principle of generating motion by attracting and repulsing magnetic cores. The SRM is characterized by the efficient use of energy in applications that require rapid changes in speed and has a higher resistance to shocks and vibrations. Among the essential factors that affect the performance of the SRM motors are the embrace of poles stator and rotor, dimensions, the size of the motor, the shapes of rotor geometry and the number of stator and rotor poles. This paper aims to study the effect of material selection on improving the SRM performance. First, we created a basic design of the SRM with appropriate characteristics to obtain the best operation conditions of high speed and torque. Then, we applied different materials and compared the obtained results using the ANSYS RMxprt tool. We focused on studying the effect of selecting materials in the rotor and stator parts on the SRM 6/4 performance through the efficiency, total losses, speed and rated torque. After comparing and analyzing the basic results, a two-dimensional model of the SRM was created using the ANSYS Maxwell 2D tool to evaluate the motor’s performance. The analysis includes the curves of torque, speed, current, flux linkages and voltage, in addition to the variation of flux lines and magnetic flux density. The results were analyzed using the finite element method (FEM), which is characterized by speed and accuracy in electromagnetic analysis and various data.</p> Layachi Chebabhi, Toufik Tayeb Naas, Mohamed Zitouni , Ismail Ghibeche, Tahar Benmessaoud Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 A contribution to the study of mortars prepared with recycled sand <p>No one denies that today concrete is the most used material in the field of civil engineering. It is widely admitted that the production of concrete necessitates large quantities of fine aggregates, specifically river sand and crushed sand. Moreover, the excessive exploitation of river sand, which generally causes a multitude of environmental problems, has pushed the majority of governments around the world to issue rules for the purpose of limiting or preventing the illegal extraction of river sand. The present article aims primarily to make a contribution to studying the possibility of replacing natural sand (NS) and crushed sand (CS) with recycled sand (RS) in ternary mortars, at proportions ranging from 20% to 100%. The consistency of the mixtures, the densities in the fresh and hardened state, the compressive strength after 3, 14 and 28 days of hardening, as well as the absorption of water by immersion and by capillarity at 28 days, were determined and discussed. It should be noted that the (W/C) ratio was set at 0.7 for all mixtures.</p> <p>The experimental results showed that recycled sand could be successfully used as an alternative to natural sand, up to a rate of 40%, for the manufacture of ternary mortars without significantly affecting their properties.</p> Boubakeur Seddik Elbahi, Leila Zeghichi, Bachir Elbahi, Radhia Djeridi Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Influence of anions and cations on the oxidation of basic blue 26 and basic violet 3 dyes by the Fenton process <p>Among the advanced oxidation processes (AOP) used to treat textile effluents, the Fenton process is particularly appreciated for its ability to effectively treat pollutants that are difficult to degrade by other conventional methods, such as synthetic dyes, especially basic or cationic dyes, which present the highest poisoning rates, underscoring the harmful nature of these substances. We conducted an examination in this context, concentrating on the impact of ions on dye degradation at a temperature of 294 K. This is because ions in solution left over from chemicals used during manufacturing processes can have a significant impact on the efficiency of the Fenton reaction, as they can act as catalysts or inhibitors of the reaction. The degradation of cationic, Basic Blue 26 (BB26) and Basic Violet 3 (BV3) dyes at an initial concentration of 10 mg/L by the Fenton process (Fe<sup>2+</sup>/ H<sub>2</sub>O<sub>2</sub>) was studied in this paper. The results showed a discolouration and degradation of 75.5% for BB26 and 45.4% for BV3 after 30 minutes. The effects of monovalent anions (Cl<sup>-</sup> and NO<sub>3</sub><sup>-</sup>), divalent anions (SO<sub>4</sub><sup>2-</sup> and CO<sub>3</sub><sup>2-</sup>), and cations (Na<sup>+</sup>, K<sup>+</sup>, and Ca<sup>2+</sup>) on degradation rates were evaluated. The decrease in degradation yield by the presence of Na<sup>+</sup>, K<sup>+</sup> and Ca<sup>2+</sup> cations and Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup> and SO<sub>4</sub><sup>2-</sup>anions for BB26 dye and by the presence of Na<sup>+</sup> and Ca<sup>2+</sup> cations and Cl<sup>-</sup> and SO<sub>4</sub><sup>2-</sup> anions for BV3 dye was discussed. On the other hand, K<sup>+</sup> and NO<sub>3</sub><sup>-</sup> ions have somewhat favoured the yield of BV3 dye degradation, while the presence of carbonate anion (CO<sub>3</sub><sup>2-</sup>) increased the degradation rate of our two dyes.</p> Kumar Djamal Belaid, Hichem Seddiki Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Evaluation of treated wastewater quality from Cap-falcon plant for agriculture irrigation <p>Wastewater reuse is a useful tool for minimizing the amount of wastewater discharged into the environment. However, it is associated with threats to the environment and public health; consequently, effluent quality assessment is essential prior to reuse. The aim of this study is to assess the physicochemical and microbiological quality of treated wastewater from Cap Falcon wastewater treatment plant for reuse in irrigation. The suitability of treated wastewater from Cap Falcon plant for irrigation was assessed based on its composition and Algerian irrigation water quality standards. The average biochemical oxygen demand (BOD<sub>5</sub>) and chemical oxygen demand (COD) values decrease from 316 mg/L to 21 mg/L with a mean removal efficiency of 93.0% and from 659 to 40 mg/L with removal efficiency of 93.7% respectively. For total suspended solids (TSS), the concentration at the inlet of the treatment plant is very high but reduces greatly after biological treatment with a removal efficiency over 94.5%. The physico-chemical analyses of treated wastewater samples from the storage reservoir indicated that pH varied from 6.81 to 8.20 with an average value of 7.43, which is slightly alkaline in nature. Electrical conductivity is one of the criteria used to evaluate the suitability of water for agricultural use; the average value was found less than 1500 μS/cm, indicating that the treated wastewater is considered as suitable for irrigation use.&nbsp; On the other hand, microbiological analyses indicate that faecal coliforms are high compared with Algerian water quality reuse standards. Furthermore, the overall quality of tertiary treated wastewater was analyzed by calculating the water quality index. The calculated index for the physicochemical and microbiological parameters was 96, which corresponds to a water quality type “very poor” signifying that this effluent can only be used for restricted irrigation practices.</p> Malika Khelladi, Khalida Bekrentchir, Amina Mezouagh, Zahira Mohamed Seghir, Driouch Aouatef, Abdelkader Debab, Abdellah Benhamou Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Improved control of permanent magnet synchronous motors using adaptive nonlinear control with Deadbeat Observer <p>Permanent Magnet Synchronous Motor (PMSM) control optimization is crucial for a variety of applications, including electric vehicles, industrial automation, and renewable energy systems (RESs). However, traditional control methods often struggle to adapt to the dynamic and non-linear nature of PMSMs, leading to sub-optimal performance. To address these challenges, this paper proposes a hybrid adaptive nonlinear control strategy with a deadbeat observer (DO) designed to improve the performance of PMSMs. This approach aims to improve the accuracy and robustness of the control while taking into account the system parameters variations and disturbances. Simulation tests comparing the proposed method with an adaptive nonlinear control (ANLC) are presented, highlighting its superior effectiveness in controlling PMSMs under varying load conditions and speed fluctuations. The proposed strategy achieves a maximum relative speed error around of 6% at 0.4 s under gradually varying load torque disturbances, which is better than the ANLC with 8%. Furthermore, under large speed variations, the suggested method maintains a maximum relative speed error of 0.82% at 0.85 s. Furthermore, the robustness assessment under system parameters variations, stator resistance, and inductance, shows extraordinary performances of the proposed scheme. These results highlight the effectiveness and robustness of the proposed strategy in achieving precise PMSM control while dynamically adapting to changing conditions. This research underscores the potential of our approach to advance key technologies, including electric vehicles, industrial automation, and renewable energy systems. By optimizing PMSM control, this strategy contributes to increased efficiency, reliability, and adaptability, facilitating broader adoption of electric propulsion systems and sustainable energy solutions.</p> Aissa Redhouane Harkat , Linda Barazan, Abdelouadoud Loukriz, Ahmed Bendib Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Solving inverse problems in magnetic field leakage sensor array inspection of petroleum tank floor <p>The MFL method is a qualitative inspection tool and is a reliable, fast, and economical nondestructive testing method for tank floors. In this paper, before presenting the defect reconstruction procedure, we studied the effect of defect parameters on the magnetic field leakage measured by a single Hall sensor. As predicted, the study of each parameter has demonstrated that any variation in the geometrical parameters of the studied defect induce a significant influence on the MFL signal amplitude and distribution; for this reason, all the defect parameters must be determined precisely and prudently. After that, we have studied the performance of defect shape reconstruction from MFL array sensor imaging and depth estimation while using an iterative inversion method. Indeed, the first stage consists of determining the defect width and length from magnetic flux leakage mapping reconstructed from the recorded signals of the micro-integrated magnetic sensors. As a second step, after coupling Comsol and Matlab software, the defect depth is obtained by coupling the 3D finite elements method and a fast iterative algorithm recently developed. Consequently, the defect shape and size are obtained after a few iterations with a relative error of less than 2%; which makes this method very appropriate for real-time defect reconstruction and quantification. Furthermore, this method of defect reconstruction and seizing can be extended for irregular shape such as cracks and corrosion. In fact, this can be done while subdividing the affected area of non-constant depth into elementary zones of a constant depths. Then, while modifying the previous algorithm, we determine the corresponding depth of each zone.&nbsp;</p> Kamel Belkhiri, Tarik Bouchala, Abdelhak Abdou, Abdelhak Abdou, Bachir Abdelhadi, Amor Guettafi , Yann Le Bihan Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Effect of glass fibers on performance of mortar and concrete <p>The recycling of waste and the reinforcement of concretes and mortars, with fibers are a technique that is increasingly being used to improve their mechanical performance, durability, reduce costs and protect the environment. Glass fibre is one of the most interesting types of fibre to use, as its use reduces the environmental impact of glass fibre waste by offering a recycling process and maintaining its valuable strength properties. This paper focused on the effect incorporating glass fibers at different dosages (0.25%, 0.5%, 0.75% and 1%) on the rheological and mechanical properties of mortar and concrete. A wide range of tests were conducted including flow time, concrete slump, compressive strengths, 3-point bending strengths, tensile strengths and microstructural characterization by scanning electron microscopy (SEM). To support the discussion of the results, an analysis of the scanning electron microscopy (SEM) image was carried out using Gwyddion software to study the adhesion between the fibers and the matrix and to analysis the heat flow distribution of fibers in the mortar and concrete matrix. The obtained results showed that the content fibers dosages had a significant effect on the rheological , mechanical properties and on the adhesion of fibers to the matrix of the mortar and concrete , with better behavior in the presence of concrete aggregates. The analysis of the SEM image using Gwyddion software shows that good distribution and the good adhesion of glass fibres in the mortar samples . In contrast, the distribution in the concrete is not regular which does not give a good adhesion to the matrix.</p> Bariza Boukni , Mohamed Lyes Kamel Khouadjia, Sara Bensalem Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Effect of the incorporation of plastic waste on the mechanical properties of composite materials <p class="referencias" style="text-align: justify;">Through this scientific research, we have tried to study the effect of the incorporation of plastic waste on the mechanical properties of concrete, in order to obtain good concrete with high resistance at a lower cost. To carry out this work, we adopted the following steps: Knowledge of the properties of concrete, which contains plastic waste of High Density Polyethylene (HDPE). Thus, the natural aggregate was replaced by concrete formulated with plastic waste in partial substitution varying between 0%, 10% and 20%. In all the concrete mixtures, the components, water, cement, gravel 3/8 and 8/15 and sand 0/3, remained constant while the HDPE waste varied according to the substitution rate. Through this process, the mechanical properties of concrete in fresh and hardened states were determined. The analysis of the results of the study allowed us to know the incorporation of plastic waste and its effect on the behaviour of the manufactured concrete. The results showed that the density of concrete made from plastic waste is lighter than the reference concrete without waste (C0), which contains only natural aggregates, in a fresh state. In the case of hardening, the results showed a decrease in the compressive strength of composite concrete produced from plastic waste compared to (C0) the reference concrete. In the study's second part, a numerical model for precision and effectiveness is constructed using the finite element (FE) method. Furthermore, manufacturing experiments are scheduled to use computer simulations that account for labour, materials, tests, and time. The nonlinear stress-strain relationship for time-dependent concrete deformations and tension cracks presents a challenge for concrete modelling. ANSYS software is used to use three-dimensional nonlinear finite elements in order to determine this kind of complex mechanical behavior.</p> Omar Safer, Ouaddah Chaib, Adda Hadj Mostefa, Mouloud Dahmane, Adem Ait Mohamed Amer, Mohamed Salhi, Mourad Benadouda, Noureddine Latroch, Abdelkader Safa Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Decentralized energy management of DC microgrids with PV, wind, BES, and fuel cell <p>Amidst the evolving energy landscape, there are an increasing demand for sustainability. With the global embrace of renewable sources such as wind and solar power, the urgency for innovative energy management solutions intensifies. This paper presents an energy management system tailored for a decentralized DC Micro-grid catering to a 10 kW DC load. The microgrid combining diverse renewable energy sources incorporating solar panels, wind turbines, battery energy storage systems (BESS), and a fuel cell serving as an emergency backup solution. The control strategy deployed for efficient operation is a PI cascade control approach. However, to optimize the performance of the controller, the parameter gains of the PI controller are enhanced using a metaheuristic algorithm, specifically the Genetic Algorithm (GA). The proposed system aims to garantuate a reliable and stable power supply to the DC load while maximizing the utilization of renewable energy sources, minimization hydrogen consumption and decreasing reliance on classical grid source. The effectiveness of the proposed energy management system is validated across simulation studies using MATLAB Simulink under various operating scenarios. These scenarios comprise serval environmental conditions, load profiles, and renewable energy availability. The simulation results demonstrate the capability of the system to efficiently manage power flow and enhance overall system performance in decentralized DC microgrid environments.</p> Taibi Abdelhalim, Laroussi Kouider, Rouibah Abdelkader, Hartani Mohamed Amine Copyright (c) 2024 Fri, 31 May 2024 00:00:00 +0000 Positive solutions for a coupled systems involving the fractional p(x)- Laplacian operator in unbounded domains <p>In this paper, we study the existence of at least one weak solution for a class of nonlocal elliptic systems involving the fractional <em>p(x)-</em>Laplacian. These operators are utilized to solve a system defined within unbounded domain. The right sides of systems treated are closely related to a type of gradient C<sup>1</sup>-functional which satisfy a sublinear growth conditions. Under some additional assumptions on the nonlinearities and leveraging the theory of Lebesgue and fractional Sobolev spaces with variable exponents, we can use a variational approach to establish the existence result.</p> Hadjira Lalili Copyright (c) 2024 Wed, 05 Jun 2024 00:00:00 +0000 Orthogonality and unitary conditions for solutions to some consistent linear matrix equations <p>The nonlinear matrix equation <em>(</em><em>A<sub>1</sub> + B<sub>1</sub>X<sub>1</sub>D<sub>1</sub>)(A<sub>2</sub> + B<sub>2</sub>X<sub>2</sub>D<sub>2</sub>) = A</em>, presents a matrix identity, where <em>A, A<sub>i</sub>, B<sub>i</sub></em>, and <em>D<sub>i</sub> </em>are known matrices of suitable sizes and <em>X<sub>i</sub></em> are unknown matrices for <em>i = 1,2</em>, over the field of complex numbers ℂ. Several known simple methods in linear algebra can handle the orthogonality problem. In this paper, we select some linear matrix equations as illustrative examples to discuss some properties of pairs of identically dimensional consistent linear matrix equations, then apply specific matrix analytic tools, among them is the matrix rank method, the rank of a matrix is one of the most basic quantities and useful methods and tools that are widely used in linear algebra specifically, in matrix theory and its applications. We consider certain forms of linear matrix equations such as <em>T</em><em><sub>1</sub></em><em>X<sub>1</sub> = N<sub>1</sub></em> and the system <em>A<sub>3</sub>X<sub>3</sub> = C<sub>3</sub>, X<sub>3</sub>B<sub>3</sub> = D<sub>3</sub></em>, to derive novel conditions dictating the orthogonality of all solutions to two consistent matrix equations, as well as the necessary and sufficient conditions for all solutions to be unitary, further we give an illustrative example.</p> Sihem Guerarra Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Wed, 05 Jun 2024 00:00:00 +0000 Uniqueness and regularity of solutions of integral equations in irregular domains using fractional Sobolev spaces <p>This paper investigates the uniqueness and regularity of solutions to integral equations associated with elliptic boundary value problems in irregular domains. While traditional studies often assume smooth boundaries, this research extends these results to domains with irregular boundaries. By utilizing Sobolev spaces, particularly fractional Sobolev spaces, and the properties of the Slobodetskii norm, a robust theoretical framework is developed. The main theorem of this study demonstrates that, under suitable conditions, the integral equation under consideration has a unique solution that inherits regularity properties. In other words, even in domains with irregular boundaries, it is possible to guarantee the existence of unique solutions with certain smoothness properties. This is crucial for the application of mathematical methods to real-world problems. These results represent a significant advancement in the mathematical understanding of boundary value problems in non-smooth domains. This has important implications, as many practical problems in physics and engineering involve domains with complex and irregular boundaries where traditional techniques are not applicable. By extending the results to irregular domains, this work opens new possibilities for the application of mathematical methods in more realistic and complex situations. The mathematical tools developed, based on fractional Sobolev spaces and the Slobodetskii norm, offer an innovative and effective approach to addressing these challenges. In summary, this study not only broadens the scope of problems that can be solved using integral equations but also provides a solid theoretical foundation for future research and applications in various scientific and technological fields. The findings presented here promise to significantly influence the development of new techniques and solutions in multiple areas of knowledge.</p> Rômulo Damasclin Chaves dos Santos Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 06 Jun 2024 00:00:00 +0000 Optimal performance of an agricultural greenhouse by testing different materials in arid and semi-arid climate <p>This comprehensive and meticulously researched study delves deeply into the multifaceted intricacies surrounding the implementation, optimization, and ongoing refinement of an innovative evaporative cooling system tailored specifically for agricultural greenhouses. Drawing upon the abundant availability of three locally sourced materials — straw, palm leaves, and wool pads — the study endeavors to establish a robust, sustainable, and eco-conscious cooling infrastructure. The overarching objective is not merely to create a cooling solution, but rather to engineer a sophisticated system capable of adeptly regulating temperature fluctuations within the greenhouse environment, thereby creating and maintaining optimal growth conditions essential for crop productivity and success. At the heart of this ambitious endeavor lies the integration of cutting-edge technology, notably a photovoltaic (PV) generator, strategically deployed to power an array of fans. This energy-efficient setup is further bolstered by an ingenious battery storage mechanism, meticulously designed to ensure seamless operation even during nocturnal hours. The evaluation process employed by the researchers is rigorous and exhaustive, meticulously scrutinizing the efficacy of each material utilized as a cooling pad. Parameters such as their ability to effectively humidify the atmosphere and lower ambient temperatures within the greenhouse confines are carefully assessed. Through a series of meticulously conducted experiments and observations, the study unveils the commendable efficiency and efficacy of the cooling system in significantly curtailing temperature differentials, thus underscoring its pivotal role in enhancing agricultural productivity and sustainability. These findings not only underscore the tangible benefits of harnessing locally available resources but also serve as a testament to the transformative potential of eco-friendly cooling solutions in mitigating the myriad challenges faced by modern agriculture. As the research horizon continues to expand, future endeavors are poised to pivot towards further fine-tuning system parameters, exploring the integration of novel materials, and devising innovative strategies aimed at enhancing cooling efficiency and sustainability within greenhouse environments. This ongoing pursuit of innovation and refinement is essential in ensuring the continued evolution and optimization of agricultural practices in an ever-changing world.</p> Djemoui Lalmi, Kamel Bouaraour, Abdelouahab Benseddik, Ahmed Badji, Hocine Bensaha, Abderahmane Zahouani, Marwa Rabehi, Khadidja Khodja Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 06 Jun 2024 00:00:00 +0000 Experimental study of the influence of the incorporation of combined recycled steel and polypropylene fibers on the compressive behavior of self-compacting cementitious composites <p>In recent times, many industries have focused on affordable materials with superior mechanical properties. Most fiber-cement composites are made from a single type of fiber. The addition of the fine elements, which must include at least one mineral addition, fewer chippings, a dosage of super plasticizing admixture, and quite often a colloidal agent, can produce very workable cementitious composites that spread without any vibration in the formwork. However, the use of several types of fiber in the composite, in different proportions, offers several environmental, technological, and economic advantages that are of growing interest to manufacturers. Improving material properties, such as impact resistance, tensile strength, compressive strength, and increased rigidity, can also contribute to a significant gain in fiber. This study aims to exploit recycled steel fiber, obtained from steel wool production waste, and polypropylene fiber, as reinforcement, together with a cementitious matrix, based on local materials, to develop a new self-compacting cementitious composite with combined fibers (steel/polypropylene). Blends of 1%, 1.5%, and 2% combined fibers were formulated with steel and polypropylene fibers. Several proportions of matrix/combined reinforcement were considered to assess the effect of the amount of combined reinforcement on destructive tests, such as compressive strength, and non-destructive tests, such as sound propagation velocity and rebound index, on the quality of these composites. The results obtained show that a combination of two different fibers can be used in self-placing cement composites as reinforcement. Finally, we determine the possibility of using non-destructive testing as a means of assessing the quality of self-placing cement composites with combined fibers (steel/polypropylene).</p> Mohamed Yagoub, Tahar Masri, Mekki Mellas, Adel Benchabane, Bachir Lamouri Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 06 Jun 2024 00:00:00 +0000 Investigation of predictive direct torque control of Double Star permanent magnet synchronous machine (DSPMSM) <p>In order to enhance the performance of Direct Torque Control (DTC) applied to a double-star permanent magnet synchronous machine (DSPMSM) in termes to reduce the ripples of torque and current, in this work we propose a Predictive DTC Control for DSPMSM. The primary objective of this control approach is to eliminate the hysteresis controllers and vector selection table commonly found in conventional DTC, addressing associated issues. This innovative strategy relies on Proportional-Integral (PI) controllers and Predictive Control, with both inverters operating at a constant frequency. In the proposed Predictive DTC Control, the predictive model is used to forecast the future behavior of the machine’s torque and current. This allows the control system to make more informed decisions regarding the optimal voltage vectors to apply, minimizing ripples and enhancing the dynamic response. The simulation results, obtained from Matlab/Simulink, demonstrate a significant improvement in the performance of the DSPMSM when using the proposed method. Key metrics such as torque ripple, current ripple, and overall system efficiency were analyzed, showing favorable outcomes compared to conventional DTC methods. The study underscores the potential of predictive control in advancing the performance of DTC systems for DSPMSMs. By leveraging the capabilities of predictive modeling and PI controllers, the proposed method not only addresses the limitations of conventional DTC but also paves the way for more advanced and reliable control strategies in electric drive applications. The findings suggest that the implementation of Predictive DTC Control could lead to more robust and efficient motor drives, which are critical for various industrial applications requiring precise and stable torque control.</p> Mohamed Ghibeche, Katia Kouzi, Djamel Difi, Abdesslam Ouanouki Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Fri, 07 Jun 2024 00:00:00 +0000 Nonparametric conditional mode estimate under doubly truncated model <p>Conditional mode function is often used in various fields such as statistics, data analysis, and machine learning to understand the distribution of data and make decisions based on specific conditions or criteria. In this paper, we propose a non-parametric kernel estimator of the conditional mode function, when the variable of interest is subject to random doubly truncation. We prove the suggested estimator's strong consistency with a rate and state its asymptotic normality under some regularity assumptions. Our results are based on special mathematical techniques such as the iterative non-parametric maximum likelihood estimators (NPMLE) of the distribution function and the Vapnik-Cervonenkis classes for which uniform exponential inequalities are available. This study will be a valuable resource for scholars and practitioners interested in non-parametric kernel estimation methods for doubly truncated data.</p> Karima Zerfaoui, Djabrane Yahia Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Fri, 07 Jun 2024 00:00:00 +0000 DJADE: a reliable and efficient adaptive differential evolution algorithm with selection pressure control <p>Our main contribution is the proposition of a new and explicit way of adapting the parental selection pressure for Differential Evolution algorithm (DE) and its experimentation on an adaptive version of differential evolution algorithm named JADE in order to improve its reliability without diminishing its efficiency. The new algorithm named DJADE employs a genotypic population diversity measure (a measure of population convergence) to control the selection pressure parameter. A mechanism that increases the parental selection pressure as the search progresses and in the same time serves as a mean to detect when the algorithm begins to converge (the "convergence phase") is presented. In addition, DJADE is a novel adaptive DE, which adapts crossover, mutation and selection pressure parameters. Moreover, the coefficient K of greediness of the mutation scheme DE/current-to- best/ is also adapted. The motivation for the parameter adaptation is to obtain an algorithm that is capable to handle various problems with different characteristics, notably difficult multimodal and/or nonseparable functions. No case of premature convergence is observed during the experiments conducted on 13 classical functions test at 05 and 30 dimensions. The comparison with classical JADE and Classical DE are presented. DJADE is not only very efficient but also reliable on all functions tested.</p> Hocine Djebar, Abdelatif Bencherif-Madani, Raouf Ziadi, Choubeila Souli Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Non-local effects on displacement in cylindrical structures <p class="referencias" style="text-align: justify;"><span style="background: white;">This study investigates the influence of non-local effects on displacement variations in polar coordinates for clamped-clamped cylinders, assuming material properties vary as a power function of the thickness coordinate. The displacement expression is derived from a solved differential equation, with particular attention given to the impact of fixation mode on displacement. The findings underscore the importance of non-local factors in determining structural behavior and stress the necessity of considering fixation mode when computing integration constants. Nonlocal effects denote interactions and influences that extend beyond locally observed conditions or alterations within a specific system. Examining clamped-clamped cylinders, this research delves into displacement variations in polar coordinates while considering the influence of non-local effects, assuming material properties change according to a power function of the thickness coordinate. The derivation of the displacement expression from a solved differential equation forms a key aspect, with a specific focus on how fixation mode affects displacement. The study's outcomes highlight the crucial role of non-local factors in shaping structural behavior and underscore the imperative of accounting for fixation mode when calculating integration constants. Focused on clamped-clamped cylinders, this study explores displacement variations in polar coordinates under the influence of non-local effects, presuming material properties to follow a power function of the thickness coordinate. Utilizing a solved differential equation, the investigation derives the displacement expression and scrutinizes how fixation mode impacts displacement. The results elucidate the pivotal significance of non-local factors in delineating structural behavior and stress the requisite consideration of fixation mode in integration constant calculations.</span></p> Zine Abdellah, Berrabah Hamza Madjid, Bouderba Bachir Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 A new intelligent scheme for short-circuit detection, classification and location in power transmission lines with the PV generation presence <p>Transmission lines constitute critical energy infrastructure in an electrical installation, as they ensure a reliable and efficient energy transition. However, they are prone to breakdowns, due to their significant length and their continuous exposure to atmospheric conditions. In addition, the photovoltaic energy sources integration can modify their behavior, which contributes to a greater increase in the breakdowns probability. Short circuits are the most common and dangerous fault type, leading in the majority of cases to other fault types. This research describes the development of a new intelligent system that consists of three stages. The first stage aim is to identify whether there is a short circuit or not using a binary SVM. In the second stage, an innovative expert system is used to determine the short circuit type among 11 potential faults. The output of this system depends on the inputs obtained by four binary SVM, each of which determines the fault presence or absence in a phase. The third stage is responsible for estimating the exact fault position in a 100 km transmission line. This stage is made up of 11 universal regressors of type MLP. The proposed system was validated using signals, obtained from a modelled High-Voltage Line with a PV Energy Source (25 kV-50 Hz-100 Km) and processed by the Discrete Wavelet Transform. Statistical metrics (with all p-value &lt; 0.001) validate the proposed system performance with: 100% sensitivity and specificity for the fault detector ; an average sensitivity, specificity, and false alarms of 99.38%, 99.94%, and 0.17%, respectively, for the fault discriminator ; and a 2.66% mean squared error and a 97.80% overall sensitivity for the fault location estimator. These results conclude the proposed approach reliability, demonstrating its potential effectiveness in real-world scenarios.</p> Sakina Behilil, Mounia Hendel, Imen Souhila Bousmaha, Khadra Kessairi, Mostefa Brahami Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Experimental validation of a real-time fuzzy logic-based MPPT controller for a PEM fuel cell emulator system <p class="referencias" style="text-align: justify;">The Fuel cells are vital in the industry due to their environmental benefits, high efficiency, energy security, operational flexibility, and long-term cost savings. Their diverse applications and contributions to innovation and economic growth further underscore their importance in the industrial sector. The development of precise emulators is essential to advance fuel cell technology, providing a robust platform for testing and optimization. These benefits contribute to the advancement of fuel cell technology and support the transition to sustainable energy systems. The implementation of MPPT in fuel cell emulators enhances efficiency, stability, and adaptability, leading to improved performance, longer lifespan, and lower operational costs. For this, in this article proposes a proton exchange membrane fuel cell emulator based on a DC-DC Buck converter controlled by a Lyapunov regulator. The emulator is connected to a boost converter and tested using a maximum power point tracking (MPPT) algorithm. A fuzzy logic MPPT controller is introduced, allowing for the extraction of the maximum available power with minimal oscillations around the optimum, irrespective of load changes. The system's effectiveness is validated under various operating conditions using the MATLAB Simulink package. Polarization characteristics obtained from the PEM fuel cell reference model illustrate the influences of temperature and oxygen pressure on the I-V and P-I characteristics. For experimental validation, a real-time test was conducted. The simulation and experimental results under different conditions are presented and analyzed.</p> Tiar Mourad, Charrouf Omar, Hasrouri Malika, Betka Achour, Fadi Mohamed Kethiri, Abdeddaim Sabrina Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Evaluation of the mechanical properties of adobe bricks when adding palm fiber and lime <p>Adobe construction is widespread in many rural areas around the world. It is characterized by being traditional and corresponds to the climatic characteristics of the regions in which it is located, as well as low energy consumption and compatibility with the principle of environmental conservation. In addition to the possibility of recycling. However, it has such disadvantages as fragility and wilting due to climatic factors. Modern research has, therefore, focused on increasing the hardness of this brick. This study aims to study the effect of using palm and lime fibers in adobe bricks. According to previous studies, it is one of the most important ways to improve the mechanical properties of adobe bricks. We are studying bricks from the Adrar region in the south of Algeria. Where we change the ratio of lime to 5%، 10%، 15%، 20%. We change the percentage of palm fibers from 0.1% to 0.5%. We determine the ideal water content and study the change in density and mechanical pressures inside a scientific laboratory using systematic experimental methods. The study focuses on determining the best ratio between palm and lime fibers, which gives us the highest hardness of the samples. Preliminary results indicate that adding palm fibers reduces the bulk density value by 0.34% to 8.53%, which makes the brick lighter. The value of mechanical stresses increases from 7.89% to 26%.The best ratio is 0.2% palm fibers to 15% lime, which is a positive ratio in terms of solidity. These results allow us to know the ideal proportions between palm fibers, lime, soil, and water so that we can take advantage of them in future studies.</p> Boukhari Ahmed, Fidjah Abdelkader, Deliou Adel, Medfouni Mohamed Nadjib, Bouldoum Imene, Abid Imene Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Estimating hazard functions in the presence of double truncation in statistical data analysis <p class="referencias" style="text-align: justify;">The motivation for studying the incompletely observed doubly truncated data arises from its prevalence in various fields such as actuarial science, engineering and astronomy. For example, in medical research the analysis of AIDS data and that of childhood cancer remains two of significant challenge for the worldwide, in these cases, only patients infected during a specific period who subsequently developed the disease are studied. Thus, the age at diagnosis is doubly truncated. In this paper, we’ll provide tow smooth estimators of the cumulative distribution function and that of hazard function under doubly truncated data. Also, we’ll conduct both numerical and theoretical comparisons between our proposed estimators and other existing estimators. A simulation study is carried out to examine the bias and root mean square error of the proposed estimators. Furthermore, an application to a real childhood cancer data set, is presented to demonstrate that our newly estimator fits better than known existing estimators.</p> Roumaissa El Bay, Djabrane Yahia Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Análise da qualidade do ar no ambiente na central de esterilização de materiais hospitalares – um estudo de caso <p>Introdução: Este trabalho visa a avaliação da qualidade de ar da Central de Material Esterilizado do HU-UFSC. Um dos objetivos essenciais das instalações de climatização é garantir qualidade do ar adequada e, em particular, reduzir os riscos biológicos e químicos transmissíveis pelo ar em níveis compatíveis com a atividade desenvolvida nas diversas áreas. Justifica-se a importância da análise de qualidade do ar tendo em vista que se estima que, apenas em 2016, a poluição do ar interior e exterior tenha causado cerca de 7 milhões de mortes no mundo e também é destacada diante do público e das atividades que caracterizam este tipo de edificação. Objetivos: Vistoriar e avaliar as instalações dos ambientes climatizados e coletar amostras, efetuar medições, avaliar resultados das análises microbiológicas, químicas e físicas do ar dos sistemas e ambientes climatizados. Métodos: Coleta de amostras em 6 pontos de amostragens através de equipamentos e metodologias em consonância com as Normas da ANVISA. Resultados e Discussão: Os resultados obtidos constam no decorrer do artigo. Nos valores apresentados na Tabela dos resultados constam os resultados brutos corrigidos a partir dos erros de medição de cada equipamento, definidos através dos respectivos certificados de calibração. Com relação ao diagnóstico microbiológico doa r conclui-se que os valores obtidos para as análises realizadas, conforme demonstrados na tabela, encontram-se em conformidade com a Resolução RE09/2003 da Anvisa. Com relação ao diagnóstico físico químico do ar conclui-se que também se encontram em conformidade com a Resolução RE09/2003 da Anvisa. Conclusão: Os resultados apresentados demonstram que os calores encontrados estão dentro dos parâmetros exigidos pela legislação vigente.</p> Davi Avelino da Silva, Antônio Renato Pereira Moro Copyright (c) 2024 Tue, 11 Jun 2024 00:00:00 +0000 Ruído e vibração ocupacional, o conforto acústico em uma central de material esterilizado, um estudo de caso <p class="referencias" style="text-align: justify;"><span style="background: white;">Os riscos no ambiente laboral podem causar danos à saúde e à integridade física do trabalhador devido à sua natureza, suscetibilidade, intensidade, tempo de exposição e concentração. O presente estudo de caso relaciona as queixas dos trabalhores em um expugo de uma Central de Material Esterelizado (CME) com as medições quantitativas de ruído e vibração, focado na principal fonte geradora dos riscos. A metodologia utilizada foi as avaliações quantitativas através de dosimetro de ruído e vibração, com a metodologia descrita nas Normas Regulamentadoras 9 e 15 do Ministério do Trabalho. Devido a necessidade de se estudar a possibilidade da existência, a médio e a longo przo de uma doeçna Ocupacional denominda Perda Auditiva Induzida por Ruído (PAIR) entre os trabalhadores que laboram no Setor referenciado, levando-se em conta que o Setor conta com um Servidor portador de perda auditiva completa, que faz uso de implante coclear, foi elaborado o presente estudo de caso que levou em cdonsideração a atividade na pior situação durante uma swemana completa, analisando o rodízio das atividades. Os resultados demonstraram a prevalência do ruído ocupacional acima dos limites de tolerância regulamentandos por Norma Rgulamentadora vigente e a vibração ocupacional em limite abaixo do limite de tolerância regulamentado, quando do uso da pistola de ar comprimido, sendo este o equipamento que produz o maior volume de ruído durante a ativiade no Setor. O período em que os ruídos ocupacionais estão acima do limite de tolerância coincide com o período em que o uso da pistola de ar comprimido para secagem dos utensílios cirúrgicos é utilizada.</span></p> Davi Avelino da Silva, Antônio Renato Pereira Moro Copyright (c) 2024 Tue, 11 Jun 2024 00:00:00 +0000 Numerical modeling of the effectiveness of recycled aggregates in reinforcing soft soil with granular columns <p>In recent years, the civil engineering field has increasingly focused on recycled aggregates due to the dwindling availability of natural aggregates and the high carbon footprint associated with their extraction and use. The use of recycled aggregates aims to decrease energy consumption and lessen the environmental impact caused by construction waste. This study illustrates the value of utilizing recycled aggregate materials for soil reinforcement and demonstrates their efficiency compared to natural aggregates. The research employs several numerical simulations carried out using PLAXIS 3D, a finite element software renowned for its advanced modeling capabilities. These simulations leverage the Mohr-Coulomb failure criteria alongside an elastic-perfectly plastic behavior model to assess the performance of various materials under different conditions. Specifically, the study investigates three types of granular columns—Ordinary Stone Columns (OSC), Sand-Fiber Mix (SFM), and Recycled Aggregate Porous Concrete Piles (RAPP)—to reinforce a unit cell model of soft soil under failure loading scenarios. Detailed analysis reveals that recycled aggregate columns exhibit a significantly higher bearing capacity, showing an improvement of up to three times that of columns made with natural aggregates. This superior performance is attributed to the enhanced mechanical properties and better load distribution capabilities of the recycled aggregates. The results are presented through load-settlement curves, which provide a clear visualization of the effectiveness of each type of granular column. Furthermore, the study highlights the practical implications of using recycled aggregates in soil reinforcement projects. The substantial improvements in bearing capacity demonstrated by the recycled aggregate columns underscore their potential as a viable and sustainable alternative to natural aggregates in various geotechnical applications.</p> Mohammed Amin Yousfi, Salim Guettala, Ali Farik, Haithem Boughezala Hamad Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 A comparative analysis of rotating airfoils focusing on aerodynamic performance and airflow patterns through 2D unsteady simulations <p>The blade section of a wind turbine plays a pivotal role in harnessing the power of the wind to generate clean and renewable energy. Each turbine blade is carefully designed with specific aerodynamic principles in mind, primarily focusing on lift and drag forces. Understanding the intricacies of aerodynamics in this context is crucial for optimizing energy capture and ensuring the overall efficiency of wind power systems. In this context the present paper investigates the aerodynamics of three airfoils named NACA-4412, NACA-23012, and NACA-63415 using numerical simulations performed with Ansys Fluent software, with a specific focus on performance and airflow patterns. Through two-dimensional unsteady simulations, the computational approach thoroughly explores the impact of rotational speeds (ranging from 2 to 16 degrees per second) and a range of Reynolds numbers from 1.25e6 to 2e6. The findings illustrate the dynamic interplay between airflow patterns and operational factors. Variations in velocity magnitude, influenced by rotational speeds and Reynolds numbers, were observed. These variations provided additional insights into flow behavior near the airfoil, including the identification of flow separation regions, as depicted by the velocity vectors. Analysis of lift coefficient values revealed a minimal variation concerning changes in rotational speed, suggesting 8 degrees per second as an appropriate rotational speed for the studied cases. Examination of airfoil aerodynamic coefficient trends highlighted noteworthy findings. Drag coefficient values exhibited an increasing variation over time, with higher values observed in the case of the NACA-63415 airfoil. On the other hand, lift coefficient values displayed an increasing variation reaching a maximum value, followed by a decreasing trend. Notably, the NACA 4412 airfoil demonstrated superior aerodynamic coefficients compared to the other studied airfoils.</p> Ahmed Taibaoui, Tahar Benmessaoud Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Tue, 11 Jun 2024 00:00:00 +0000 Effect of bentonite on thermal conductivity, mechanical strength and acid resistance of cement mortar <p>Cement industry generates a serious problem for the environment. Its production, through the calcination of limestone rocks and the energy used, releases a significant amount of carbon dioxide, contributing to the greenhouse effect. Finding solutions to reduce the quantity of cement necessary for the manufacture of mortar can minimize energy consumption, reduce pollution and thus preserve the environment. The aim of this experimental work was to partially replace the cement with bentonite in mortars at varying percentages of 0%, 5%, 10%, 15%, 20%, 25%, and 30%. The effects of bentonite on mechanical strengths, such as compressive and flexural strengths, as well as on thermal performance by assessing the thermal conductivity coefficient were investigated. In addition, the durability performance of mortar with and without bentonite subjected to acid solutions was also evaluated by measuring the mass loss and compressive strength before and after immersion in hydrochloric and sulfuric acid solutions. The experimental results showed that the partial replacement of cement with bentonite significantly improved the thermal insulation of mortars, since the thermal conductivity decreased from 1.59 to 1.29 w/mK. However, the mechanical strengths decreased slightly as the bentonite content increased until 15% replacement. Beyond 15% replacement of cement with bentonite, the compressive and flexural strengths decrease abruptly. The durability under an acid solutions of mortar containing bentonite is enhanced. Also, depending on the environment, the mass and compressive strength losses are largest in HCL solution and are smallest in the H<sub>2</sub>SO<sub>4</sub> solution. Finally, the durability of the mortar with bentonite is critical since water absorption increases.</p> Omar Bouksani, Benhadji Maissen, Hadja Kawthar, Kharchi Fattoum, Abba Fatiha Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 13 Jun 2024 00:00:00 +0000 Variable speed wind turbine based on doubly fed induction generator using genetic algorithms <p>Optimization of the control of doubly fed induction generators (DFIGs) is essential for many applications, such as renewable energy systems, industrial automation, and electric cars. Unfortunately, the dynamic and non-linear character of DFIG frequently makes it difficult for conventional control techniques to adjust, which results in less-than-ideal performance. To overcome these obstacles, this paper presents an optimized fuzzy speed control of a doubly fed induction wind generator using a genetic algorithm, which has more advantages than its counterpart PI speed controller. In this study, the modeling of generator in the Park's frame was presented, as well as its indirect vector control applied to the stator flux. Then, to guarantee tracking of the ideal operating point in real-time and to produce the most electricity possible for varying wind speeds, we used a fuzzy PI speed controller. To improve the sizing operation of this controller, we opted for the genetic algorithm technique combined with one of the local search methods, which facilitated the search and reduced the effort compared to the trial-and-error sizing method. Furthermore, this made it possible for the wind system to track the optimal power point maximum with good performance. The simulation results of the suggested control displayed by MATLAB-Simulink illustrate the effectiveness and adaptability of the proposed control scheme across different operating conditions. The analysis of the results showed good performance for speed, small voltage and current ripple when using the fuzzy PI speed controller with genetic algorithm technique. offering promising prospects for practical implementation in variable speed wind turbine applications.</p> Cherif Cheikh, Benalia M’hamdi, Khadar Saad Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 13 Jun 2024 00:00:00 +0000 Bounded solutions for semilinear differential equations <p>A pseudo almost periodic function is the sum of an almost periodic function and of an ergotic perturbation. An asymptotically a.p. (almost periodic) function is the sum of an almost periodic function and another zero at infinity. The asymptotically a.a. (almost automorphic) and pseudo almost automorphic functions generalized the one of asymptotically a.p and pseudo a.p functions. In this paper, we study the existence of asymptotically a.p., asymptotically a.a., pseudo a.p., and pseudo a.a. mild solutions for a class of semilinear differential equations with a second term which is each time of the same nature as the desired solution. We stady after that the regular dependence of this solution with the initial value. more precisely when the initial conditions is a asymptotically a.p., asymptotically a.a., pseudo a.p., pseudo a.a. functions we study the differentiable dependence of asymptotically a.p., asymptotically a.a., pseudo a.p., pseudo a.a. solutions of our equation. In presenting our principal result, we delve into the proprieties of the superposition operator, alternatively referred to as the Nemytskii operator, within our defined space. Additionally, we emphasize the concept of derivation associated with this operator in the spaces of asymptotically a.p., asymptotically a.a., pseudo a.p., and pseudo a.a. functions . Furthermore, our paper incorporates the utilization of semi-groups, recognized as significant assets in the domain of differential equations. The principle of this work is to transfer our equation (dynamic system problem) to an operator between the spaces used before (functional analysis problem), and to apply the implicit function theorem of the differential of calculus in Banach spaces.</p> Souhila Boudjema, Abdelkader Bouadi Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 13 Jun 2024 00:00:00 +0000 Energy decay of one-dimensional thermoelastic bresse system with distributed neutral delay and a second sound <p>In this paper we study the exponential stability of a one-dimensional thermoelastic Bresse system, with distributed neutral delay and a second sound, under suitable assumptions on the kernel of neutral delay term. In 1859, Bresse developed the circular arc problem which consists of three wave equations where the main variables, represent the vertical, longitudinal and shear angle displacements respectively. The Bresse system reduces to the well-known Timoshenko system where the longitudinal displacement <strong>w</strong> is not considered (l = 0), on the other hand, the energy associated with this system remains constant when the time <strong><em>t </em></strong>evolves, because it is an undamped system. That’s why, different types of dampings should be added to the equations or at the limit, in order to stabilize this system that has been studied by many authors. Many research has looked at the impact of the delay term on the asymptotic behavior of solutions that lead to instability in systems that are uniformly stable in the absence of delay. There are other types of discrete delays in addition to the well-known discrete delays, here we are interested in the neutral delay, which occurs in the second (highest) derivative. We establish the well-posedness result using the Faedo-Galerkin method, in this section we present our assumptions on both kernels and we are needed to announce some lemma, which will be used in the next sections, in order to make the computations easier. Then, we use the multiplier method to establish an exponential stability results although the delay is a source of instability, we show that the dissipation given by the combination of neutral delay with the heat effect and the frictional damping stabilize exponentially the system in the case of equal wave speeds by introducing a suitable Lyaponov functional. Other than that, the system’s exponential stability is lacking.</p> Abdelli Manel, Bouzettouta Lamine Copyright (c) 2024 STUDIES IN ENGINEERING AND EXACT SCIENCES Thu, 13 Jun 2024 00:00:00 +0000 Editorial <p>.</p> Barbara Bonfim Copyright (c) 2024 Tue, 02 Jan 2024 00:00:00 +0000